CLI11.h

// CLI11: Version 2.3.1
// Originally designed by Henry Schreiner
// https://github.com/CLIUtils/CLI11
//
// This is a standalone header file generated by MakeSingleHeader.py in CLI11/scripts
// from: v2.3.1
//
// CLI11 2.3.1 Copyright (c) 2017-2022 University of Cincinnati, developed by Henry
// Schreiner under NSF AWARD 1414736. All rights reserved.
//
// Redistribution and use in source and binary forms of CLI11, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holder nor the names of its contributors
//    may be used to endorse or promote products derived from this software without
//    specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// This header is not meant to be included in a .h file, to guard against
// conflicts if a program includes their own CLI11 header and then transitively
// includes this header.
#ifdef PXR_CLI11_H
#error This file should only be included once in any given source (.cpp) file.
#endif
#define PXR_CLI11_H

#pragma once

// Standard combined includes:
#include <functional>
#include <locale>
#include <cstdint>
#include <iomanip>
#include <memory>
#include <exception>
#include <stdexcept>
#include <string>
#include <vector>
#include <iterator>
#include <algorithm>
#include <sstream>
#include <cmath>
#include <type_traits>
#include <limits>
#include <set>
#include <utility>
#include <map>
#include <iostream>
#include <numeric>
#include <fstream>
#include <tuple>

#include "pxr/pxr.h"

// Guard against possible conflicts if this header is included in the
// same file as another CLI11 header.
#ifdef CLI11_VERSION
#error This file cannot be included alongside a different CLI11 header.
#endif

#define CLI11_VERSION_MAJOR 2
#define CLI11_VERSION_MINOR 3
#define CLI11_VERSION_PATCH 1
#define CLI11_VERSION "2.3.1"




// The following version macro is very similar to the one in pybind11
#if !(defined(_MSC_VER) && __cplusplus == 199711L) && !defined(__INTEL_COMPILER)
#if __cplusplus >= 201402L
#define CLI11_CPP14
#if __cplusplus >= 201703L
#define CLI11_CPP17
#if __cplusplus > 201703L
#define CLI11_CPP20
#endif
#endif
#endif
#elif defined(_MSC_VER) && __cplusplus == 199711L
// MSVC sets _MSVC_LANG rather than __cplusplus (supposedly until the standard is fully implemented)
// Unless you use the /Zc:__cplusplus flag on Visual Studio 2017 15.7 Preview 3 or newer
#if _MSVC_LANG >= 201402L
#define CLI11_CPP14
#if _MSVC_LANG > 201402L && _MSC_VER >= 1910
#define CLI11_CPP17
#if _MSVC_LANG > 201703L && _MSC_VER >= 1910
#define CLI11_CPP20
#endif
#endif
#endif
#endif

#if defined(CLI11_CPP14)
#define CLI11_DEPRECATED(reason) [[deprecated(reason)]]
#elif defined(_MSC_VER)
#define CLI11_DEPRECATED(reason) __declspec(deprecated(reason))
#else
#define CLI11_DEPRECATED(reason) __attribute__((deprecated(reason)))
#endif

// GCC < 10 doesn't ignore this in unevaluated contexts
#if !defined(CLI11_CPP17) ||                                                                                           \
    (defined(__GNUC__) && !defined(__llvm__) && !defined(__INTEL_COMPILER) && __GNUC__ < 10 && __GNUC__ > 4)
#define CLI11_NODISCARD
#else
#define CLI11_NODISCARD [[nodiscard]]
#endif

#ifndef CLI11_USE_STATIC_RTTI
#if(defined(_HAS_STATIC_RTTI) && _HAS_STATIC_RTTI)
#define CLI11_USE_STATIC_RTTI 1
#elif defined(__cpp_rtti)
#if(defined(_CPPRTTI) && _CPPRTTI == 0)
#define CLI11_USE_STATIC_RTTI 1
#else
#define CLI11_USE_STATIC_RTTI 0
#endif
#elif(defined(__GCC_RTTI) && __GXX_RTTI)
#define CLI11_USE_STATIC_RTTI 0
#else
#define CLI11_USE_STATIC_RTTI 1
#endif
#endif

#ifdef CLI11_COMPILE
#define CLI11_INLINE
#else
#define CLI11_INLINE inline
#endif



// C standard library
// Only needed for existence checking
#if defined CLI11_CPP17 && defined __has_include && !defined CLI11_HAS_FILESYSTEM
#if __has_include(<filesystem>)
// Filesystem cannot be used if targeting macOS < 10.15
#if defined __MAC_OS_X_VERSION_MIN_REQUIRED && __MAC_OS_X_VERSION_MIN_REQUIRED < 101500
#define CLI11_HAS_FILESYSTEM 0
#elif defined(__wasi__)
// As of wasi-sdk-14, filesystem is not implemented
#define CLI11_HAS_FILESYSTEM 0
#else
#include <filesystem>
#if defined __cpp_lib_filesystem && __cpp_lib_filesystem >= 201703
#if defined _GLIBCXX_RELEASE && _GLIBCXX_RELEASE >= 9
#define CLI11_HAS_FILESYSTEM 1
#elif defined(__GLIBCXX__)
// if we are using gcc and Version <9 default to no filesystem
#define CLI11_HAS_FILESYSTEM 0
#else
#define CLI11_HAS_FILESYSTEM 1
#endif
#else
#define CLI11_HAS_FILESYSTEM 0
#endif
#endif
#endif
#endif

#if defined CLI11_HAS_FILESYSTEM && CLI11_HAS_FILESYSTEM > 0
#include <filesystem>  // NOLINT(build/include)
#else
#include <sys/stat.h>
#include <sys/types.h>
#endif

// Isolate symbols from other translation units that may have included their
// own copy of CLI11 by wrapping in the pxr namespace as well as a secondary
// hard-coded namespace. The latter is needed in case the outer pxr namespace
// has been disabled.
PXR_NAMESPACE_OPEN_SCOPE

namespace pxr_CLI {

namespace CLI {


namespace enums {

template <typename T, typename = typename std::enable_if<std::is_enum<T>::value>::type>
std::ostream &operator<<(std::ostream &in, const T &item) {
    // make sure this is out of the detail namespace otherwise it won't be found when needed
    return in << static_cast<typename std::underlying_type<T>::type>(item);
}

}  // namespace enums

using enums::operator<<;

namespace detail {
constexpr int expected_max_vector_size{1 << 29};
// Based on http://stackoverflow.com/questions/236129/split-a-string-in-c
CLI11_INLINE std::vector<std::string> split(const std::string &s, char delim);

template <typename T> std::string join(const T &v, std::string delim = ",") {
    std::ostringstream s;
    auto beg = std::begin(v);
    auto end = std::end(v);
    if(beg != end)
        s << *beg++;
    while(beg != end) {
        s << delim << *beg++;
    }
    return s.str();
}

template <typename T,
          typename Callable,
          typename = typename std::enable_if<!std::is_constructible<std::string, Callable>::value>::type>
std::string join(const T &v, Callable func, std::string delim = ",") {
    std::ostringstream s;
    auto beg = std::begin(v);
    auto end = std::end(v);
    auto loc = s.tellp();
    while(beg != end) {
        auto nloc = s.tellp();
        if(nloc > loc) {
            s << delim;
            loc = nloc;
        }
        s << func(*beg++);
    }
    return s.str();
}

template <typename T> std::string rjoin(const T &v, std::string delim = ",") {
    std::ostringstream s;
    for(std::size_t start = 0; start < v.size(); start++) {
        if(start > 0)
            s << delim;
        s << v[v.size() - start - 1];
    }
    return s.str();
}

// Based roughly on http://stackoverflow.com/questions/25829143/c-trim-whitespace-from-a-string

CLI11_INLINE std::string &ltrim(std::string &str);

CLI11_INLINE std::string &ltrim(std::string &str, const std::string &filter);

CLI11_INLINE std::string &rtrim(std::string &str);

CLI11_INLINE std::string &rtrim(std::string &str, const std::string &filter);

inline std::string &trim(std::string &str) { return ltrim(rtrim(str)); }

inline std::string &trim(std::string &str, const std::string filter) { return ltrim(rtrim(str, filter), filter); }

inline std::string trim_copy(const std::string &str) {
    std::string s = str;
    return trim(s);
}

CLI11_INLINE std::string &remove_quotes(std::string &str);

CLI11_INLINE std::string fix_newlines(const std::string &leader, std::string input);

inline std::string trim_copy(const std::string &str, const std::string &filter) {
    std::string s = str;
    return trim(s, filter);
}
CLI11_INLINE std::ostream &
format_help(std::ostream &out, std::string name, const std::string &description, std::size_t wid);

CLI11_INLINE std::ostream &format_aliases(std::ostream &out, const std::vector<std::string> &aliases, std::size_t wid);

template <typename T> bool valid_first_char(T c) { return ((c != '-') && (c != '!') && (c != ' ') && c != '\n'); }

template <typename T> bool valid_later_char(T c) {
    // = and : are value separators, { has special meaning for option defaults,
    // and \n would just be annoying to deal with in many places allowing space here has too much potential for
    // inadvertent entry errors and bugs
    return ((c != '=') && (c != ':') && (c != '{') && (c != ' ') && c != '\n');
}

CLI11_INLINE bool valid_name_string(const std::string &str);

inline bool valid_alias_name_string(const std::string &str) {
    static const std::string badChars(std::string("\n") + '\0');
    return (str.find_first_of(badChars) == std::string::npos);
}

inline bool is_separator(const std::string &str) {
    static const std::string sep("%%");
    return (str.empty() || str == sep);
}

inline bool isalpha(const std::string &str) {
    return std::all_of(str.begin(), str.end(), [](char c) { return std::isalpha(c, std::locale()); });
}

inline std::string to_lower(std::string str) {
    std::transform(std::begin(str), std::end(str), std::begin(str), [](const std::string::value_type &x) {
        return std::tolower(x, std::locale());
    });
    return str;
}

inline std::string remove_underscore(std::string str) {
    str.erase(std::remove(std::begin(str), std::end(str), '_'), std::end(str));
    return str;
}

CLI11_INLINE std::string find_and_replace(std::string str, std::string from, std::string to);

inline bool has_default_flag_values(const std::string &flags) {
    return (flags.find_first_of("{!") != std::string::npos);
}

CLI11_INLINE void remove_default_flag_values(std::string &flags);

CLI11_INLINE std::ptrdiff_t find_member(std::string name,
                                        const std::vector<std::string> names,
                                        bool ignore_case = false,
                                        bool ignore_underscore = false);

template <typename Callable> inline std::string find_and_modify(std::string str, std::string trigger, Callable modify) {
    std::size_t start_pos = 0;
    while((start_pos = str.find(trigger, start_pos)) != std::string::npos) {
        start_pos = modify(str, start_pos);
    }
    return str;
}

CLI11_INLINE std::vector<std::string> split_up(std::string str, char delimiter = '\0');

CLI11_INLINE std::size_t escape_detect(std::string &str, std::size_t offset);

CLI11_INLINE std::string &add_quotes_if_needed(std::string &str);

}  // namespace detail




namespace detail {
CLI11_INLINE std::vector<std::string> split(const std::string &s, char delim) {
    std::vector<std::string> elems;
    // Check to see if empty string, give consistent result
    if(s.empty()) {
        elems.emplace_back();
    } else {
        std::stringstream ss;
        ss.str(s);
        std::string item;
        while(std::getline(ss, item, delim)) {
            elems.push_back(item);
        }
    }
    return elems;
}

CLI11_INLINE std::string &ltrim(std::string &str) {
    auto it = std::find_if(str.begin(), str.end(), [](char ch) { return !std::isspace<char>(ch, std::locale()); });
    str.erase(str.begin(), it);
    return str;
}

CLI11_INLINE std::string &ltrim(std::string &str, const std::string &filter) {
    auto it = std::find_if(str.begin(), str.end(), [&filter](char ch) { return filter.find(ch) == std::string::npos; });
    str.erase(str.begin(), it);
    return str;
}

CLI11_INLINE std::string &rtrim(std::string &str) {
    auto it = std::find_if(str.rbegin(), str.rend(), [](char ch) { return !std::isspace<char>(ch, std::locale()); });
    str.erase(it.base(), str.end());
    return str;
}

CLI11_INLINE std::string &rtrim(std::string &str, const std::string &filter) {
    auto it =
        std::find_if(str.rbegin(), str.rend(), [&filter](char ch) { return filter.find(ch) == std::string::npos; });
    str.erase(it.base(), str.end());
    return str;
}

CLI11_INLINE std::string &remove_quotes(std::string &str) {
    if(str.length() > 1 && (str.front() == '"' || str.front() == '\'')) {
        if(str.front() == str.back()) {
            str.pop_back();
            str.erase(str.begin(), str.begin() + 1);
        }
    }
    return str;
}

CLI11_INLINE std::string fix_newlines(const std::string &leader, std::string input) {
    std::string::size_type n = 0;
    while(n != std::string::npos && n < input.size()) {
        n = input.find('\n', n);
        if(n != std::string::npos) {
            input = input.substr(0, n + 1) + leader + input.substr(n + 1);
            n += leader.size();
        }
    }
    return input;
}

CLI11_INLINE std::ostream &
format_help(std::ostream &out, std::string name, const std::string &description, std::size_t wid) {
    name = "  " + name;
    out << std::setw(static_cast<int>(wid)) << std::left << name;
    if(!description.empty()) {
        if(name.length() >= wid)
            out << "\n" << std::setw(static_cast<int>(wid)) << "";
        for(const char c : description) {
            out.put(c);
            if(c == '\n') {
                out << std::setw(static_cast<int>(wid)) << "";
            }
        }
    }
    out << "\n";
    return out;
}

CLI11_INLINE std::ostream &format_aliases(std::ostream &out, const std::vector<std::string> &aliases, std::size_t wid) {
    if(!aliases.empty()) {
        out << std::setw(static_cast<int>(wid)) << "     aliases: ";
        bool front = true;
        for(const auto &alias : aliases) {
            if(!front) {
                out << ", ";
            } else {
                front = false;
            }
            out << detail::fix_newlines("              ", alias);
        }
        out << "\n";
    }
    return out;
}

CLI11_INLINE bool valid_name_string(const std::string &str) {
    if(str.empty() || !valid_first_char(str[0])) {
        return false;
    }
    auto e = str.end();
    for(auto c = str.begin() + 1; c != e; ++c)
        if(!valid_later_char(*c))
            return false;
    return true;
}

CLI11_INLINE std::string find_and_replace(std::string str, std::string from, std::string to) {

    std::size_t start_pos = 0;

    while((start_pos = str.find(from, start_pos)) != std::string::npos) {
        str.replace(start_pos, from.length(), to);
        start_pos += to.length();
    }

    return str;
}

CLI11_INLINE void remove_default_flag_values(std::string &flags) {
    auto loc = flags.find_first_of('{', 2);
    while(loc != std::string::npos) {
        auto finish = flags.find_first_of("},", loc + 1);
        if((finish != std::string::npos) && (flags[finish] == '}')) {
            flags.erase(flags.begin() + static_cast<std::ptrdiff_t>(loc),
                        flags.begin() + static_cast<std::ptrdiff_t>(finish) + 1);
        }
        loc = flags.find_first_of('{', loc + 1);
    }
    flags.erase(std::remove(flags.begin(), flags.end(), '!'), flags.end());
}

CLI11_INLINE std::ptrdiff_t
find_member(std::string name, const std::vector<std::string> names, bool ignore_case, bool ignore_underscore) {
    auto it = std::end(names);
    if(ignore_case) {
        if(ignore_underscore) {
            name = detail::to_lower(detail::remove_underscore(name));
            it = std::find_if(std::begin(names), std::end(names), [&name](std::string local_name) {
                return detail::to_lower(detail::remove_underscore(local_name)) == name;
            });
        } else {
            name = detail::to_lower(name);
            it = std::find_if(std::begin(names), std::end(names), [&name](std::string local_name) {
                return detail::to_lower(local_name) == name;
            });
        }

    } else if(ignore_underscore) {
        name = detail::remove_underscore(name);
        it = std::find_if(std::begin(names), std::end(names), [&name](std::string local_name) {
            return detail::remove_underscore(local_name) == name;
        });
    } else {
        it = std::find(std::begin(names), std::end(names), name);
    }

    return (it != std::end(names)) ? (it - std::begin(names)) : (-1);
}

CLI11_INLINE std::vector<std::string> split_up(std::string str, char delimiter) {

    const std::string delims("\'\"`");
    auto find_ws = [delimiter](char ch) {
        return (delimiter == '\0') ? std::isspace<char>(ch, std::locale()) : (ch == delimiter);
    };
    trim(str);

    std::vector<std::string> output;
    bool embeddedQuote = false;
    char keyChar = ' ';
    while(!str.empty()) {
        if(delims.find_first_of(str[0]) != std::string::npos) {
            keyChar = str[0];
            auto end = str.find_first_of(keyChar, 1);
            while((end != std::string::npos) && (str[end - 1] == '\\')) {  // deal with escaped quotes
                end = str.find_first_of(keyChar, end + 1);
                embeddedQuote = true;
            }
            if(end != std::string::npos) {
                output.push_back(str.substr(1, end - 1));
                if(end + 2 < str.size()) {
                    str = str.substr(end + 2);
                } else {
                    str.clear();
                }

            } else {
                output.push_back(str.substr(1));
                str = "";
            }
        } else {
            auto it = std::find_if(std::begin(str), std::end(str), find_ws);
            if(it != std::end(str)) {
                std::string value = std::string(str.begin(), it);
                output.push_back(value);
                str = std::string(it + 1, str.end());
            } else {
                output.push_back(str);
                str = "";
            }
        }
        // transform any embedded quotes into the regular character
        if(embeddedQuote) {
            output.back() = find_and_replace(output.back(), std::string("\\") + keyChar, std::string(1, keyChar));
            embeddedQuote = false;
        }
        trim(str);
    }
    return output;
}

CLI11_INLINE std::size_t escape_detect(std::string &str, std::size_t offset) {
    auto next = str[offset + 1];
    if((next == '\"') || (next == '\'') || (next == '`')) {
        auto astart = str.find_last_of("-/ \"\'`", offset - 1);
        if(astart != std::string::npos) {
            if(str[astart] == ((str[offset] == '=') ? '-' : '/'))
                str[offset] = ' ';  // interpret this as a space so the split_up works properly
        }
    }
    return offset + 1;
}

CLI11_INLINE std::string &add_quotes_if_needed(std::string &str) {
    if((str.front() != '"' && str.front() != '\'') || str.front() != str.back()) {
        char quote = str.find('"') < str.find('\'') ? '\'' : '"';
        if(str.find(' ') != std::string::npos) {
            str.insert(0, 1, quote);
            str.append(1, quote);
        }
    }
    return str;
}

}  // namespace detail



// Use one of these on all error classes.
// These are temporary and are undef'd at the end of this file.
#define CLI11_ERROR_DEF(parent, name)                                                                                  \
  protected:                                                                                                           \
    name(std::string ename, std::string msg, int exit_code) : parent(std::move(ename), std::move(msg), exit_code) {}   \
    name(std::string ename, std::string msg, ExitCodes exit_code)                                                      \
        : parent(std::move(ename), std::move(msg), exit_code) {}                                                       \
                                                                                                                       \
  public:                                                                                                              \
    name(std::string msg, ExitCodes exit_code) : parent(#name, std::move(msg), exit_code) {}                           \
    name(std::string msg, int exit_code) : parent(#name, std::move(msg), exit_code) {}

// This is added after the one above if a class is used directly and builds its own message
#define CLI11_ERROR_SIMPLE(name)                                                                                       \
    explicit name(std::string msg) : name(#name, msg, ExitCodes::name) {}

enum class ExitCodes {
    Success = 0,
    IncorrectConstruction = 100,
    BadNameString,
    OptionAlreadyAdded,
    FileError,
    ConversionError,
    ValidationError,
    RequiredError,
    RequiresError,
    ExcludesError,
    ExtrasError,
    ConfigError,
    InvalidError,
    HorribleError,
    OptionNotFound,
    ArgumentMismatch,
    BaseClass = 127
};

// Error definitions


class Error : public std::runtime_error {
    int actual_exit_code;
    std::string error_name{"Error"};

  public:
    CLI11_NODISCARD int get_exit_code() const { return actual_exit_code; }

    CLI11_NODISCARD std::string get_name() const { return error_name; }

    Error(std::string name, std::string msg, int exit_code = static_cast<int>(ExitCodes::BaseClass))
        : runtime_error(msg), actual_exit_code(exit_code), error_name(std::move(name)) {}

    Error(std::string name, std::string msg, ExitCodes exit_code) : Error(name, msg, static_cast<int>(exit_code)) {}
};

// Note: Using Error::Error constructors does not work on GCC 4.7

class ConstructionError : public Error {
    CLI11_ERROR_DEF(Error, ConstructionError)
};

class IncorrectConstruction : public ConstructionError {
    CLI11_ERROR_DEF(ConstructionError, IncorrectConstruction)
    CLI11_ERROR_SIMPLE(IncorrectConstruction)
    static IncorrectConstruction PositionalFlag(std::string name) {
        return IncorrectConstruction(name + ": Flags cannot be positional");
    }
    static IncorrectConstruction Set0Opt(std::string name) {
        return IncorrectConstruction(name + ": Cannot set 0 expected, use a flag instead");
    }
    static IncorrectConstruction SetFlag(std::string name) {
        return IncorrectConstruction(name + ": Cannot set an expected number for flags");
    }
    static IncorrectConstruction ChangeNotVector(std::string name) {
        return IncorrectConstruction(name + ": You can only change the expected arguments for vectors");
    }
    static IncorrectConstruction AfterMultiOpt(std::string name) {
        return IncorrectConstruction(
            name + ": You can't change expected arguments after you've changed the multi option policy!");
    }
    static IncorrectConstruction MissingOption(std::string name) {
        return IncorrectConstruction("Option " + name + " is not defined");
    }
    static IncorrectConstruction MultiOptionPolicy(std::string name) {
        return IncorrectConstruction(name + ": multi_option_policy only works for flags and exact value options");
    }
};

class BadNameString : public ConstructionError {
    CLI11_ERROR_DEF(ConstructionError, BadNameString)
    CLI11_ERROR_SIMPLE(BadNameString)
    static BadNameString OneCharName(std::string name) { return BadNameString("Invalid one char name: " + name); }
    static BadNameString BadLongName(std::string name) { return BadNameString("Bad long name: " + name); }
    static BadNameString DashesOnly(std::string name) {
        return BadNameString("Must have a name, not just dashes: " + name);
    }
    static BadNameString MultiPositionalNames(std::string name) {
        return BadNameString("Only one positional name allowed, remove: " + name);
    }
};

class OptionAlreadyAdded : public ConstructionError {
    CLI11_ERROR_DEF(ConstructionError, OptionAlreadyAdded)
    explicit OptionAlreadyAdded(std::string name)
        : OptionAlreadyAdded(name + " is already added", ExitCodes::OptionAlreadyAdded) {}
    static OptionAlreadyAdded Requires(std::string name, std::string other) {
        return {name + " requires " + other, ExitCodes::OptionAlreadyAdded};
    }
    static OptionAlreadyAdded Excludes(std::string name, std::string other) {
        return {name + " excludes " + other, ExitCodes::OptionAlreadyAdded};
    }
};

// Parsing errors

class ParseError : public Error {
    CLI11_ERROR_DEF(Error, ParseError)
};

// Not really "errors"

class Success : public ParseError {
    CLI11_ERROR_DEF(ParseError, Success)
    Success() : Success("Successfully completed, should be caught and quit", ExitCodes::Success) {}
};

class CallForHelp : public Success {
    CLI11_ERROR_DEF(Success, CallForHelp)
    CallForHelp() : CallForHelp("This should be caught in your main function, see examples", ExitCodes::Success) {}
};

class CallForAllHelp : public Success {
    CLI11_ERROR_DEF(Success, CallForAllHelp)
    CallForAllHelp()
        : CallForAllHelp("This should be caught in your main function, see examples", ExitCodes::Success) {}
};

class CallForVersion : public Success {
    CLI11_ERROR_DEF(Success, CallForVersion)
    CallForVersion()
        : CallForVersion("This should be caught in your main function, see examples", ExitCodes::Success) {}
};

class RuntimeError : public ParseError {
    CLI11_ERROR_DEF(ParseError, RuntimeError)
    explicit RuntimeError(int exit_code = 1) : RuntimeError("Runtime error", exit_code) {}
};

class FileError : public ParseError {
    CLI11_ERROR_DEF(ParseError, FileError)
    CLI11_ERROR_SIMPLE(FileError)
    static FileError Missing(std::string name) { return FileError(name + " was not readable (missing?)"); }
};

class ConversionError : public ParseError {
    CLI11_ERROR_DEF(ParseError, ConversionError)
    CLI11_ERROR_SIMPLE(ConversionError)
    ConversionError(std::string member, std::string name)
        : ConversionError("The value " + member + " is not an allowed value for " + name) {}
    ConversionError(std::string name, std::vector<std::string> results)
        : ConversionError("Could not convert: " + name + " = " + detail::join(results)) {}
    static ConversionError TooManyInputsFlag(std::string name) {
        return ConversionError(name + ": too many inputs for a flag");
    }
    static ConversionError TrueFalse(std::string name) {
        return ConversionError(name + ": Should be true/false or a number");
    }
};

class ValidationError : public ParseError {
    CLI11_ERROR_DEF(ParseError, ValidationError)
    CLI11_ERROR_SIMPLE(ValidationError)
    explicit ValidationError(std::string name, std::string msg) : ValidationError(name + ": " + msg) {}
};

class RequiredError : public ParseError {
    CLI11_ERROR_DEF(ParseError, RequiredError)
    explicit RequiredError(std::string name) : RequiredError(name + " is required", ExitCodes::RequiredError) {}
    static RequiredError Subcommand(std::size_t min_subcom) {
        if(min_subcom == 1) {
            return RequiredError("A subcommand");
        }
        return {"Requires at least " + std::to_string(min_subcom) + " subcommands", ExitCodes::RequiredError};
    }
    static RequiredError
    Option(std::size_t min_option, std::size_t max_option, std::size_t used, const std::string &option_list) {
        if((min_option == 1) && (max_option == 1) && (used == 0))
            return RequiredError("Exactly 1 option from [" + option_list + "]");
        if((min_option == 1) && (max_option == 1) && (used > 1)) {
            return {"Exactly 1 option from [" + option_list + "] is required and " + std::to_string(used) +
                        " were given",
                    ExitCodes::RequiredError};
        }
        if((min_option == 1) && (used == 0))
            return RequiredError("At least 1 option from [" + option_list + "]");
        if(used < min_option) {
            return {"Requires at least " + std::to_string(min_option) + " options used and only " +
                        std::to_string(used) + "were given from [" + option_list + "]",
                    ExitCodes::RequiredError};
        }
        if(max_option == 1)
            return {"Requires at most 1 options be given from [" + option_list + "]", ExitCodes::RequiredError};

        return {"Requires at most " + std::to_string(max_option) + " options be used and " + std::to_string(used) +
                    "were given from [" + option_list + "]",
                ExitCodes::RequiredError};
    }
};

class ArgumentMismatch : public ParseError {
    CLI11_ERROR_DEF(ParseError, ArgumentMismatch)
    CLI11_ERROR_SIMPLE(ArgumentMismatch)
    ArgumentMismatch(std::string name, int expected, std::size_t received)
        : ArgumentMismatch(expected > 0 ? ("Expected exactly " + std::to_string(expected) + " arguments to " + name +
                                           ", got " + std::to_string(received))
                                        : ("Expected at least " + std::to_string(-expected) + " arguments to " + name +
                                           ", got " + std::to_string(received)),
                           ExitCodes::ArgumentMismatch) {}

    static ArgumentMismatch AtLeast(std::string name, int num, std::size_t received) {
        return ArgumentMismatch(name + ": At least " + std::to_string(num) + " required but received " +
                                std::to_string(received));
    }
    static ArgumentMismatch AtMost(std::string name, int num, std::size_t received) {
        return ArgumentMismatch(name + ": At Most " + std::to_string(num) + " required but received " +
                                std::to_string(received));
    }
    static ArgumentMismatch TypedAtLeast(std::string name, int num, std::string type) {
        return ArgumentMismatch(name + ": " + std::to_string(num) + " required " + type + " missing");
    }
    static ArgumentMismatch FlagOverride(std::string name) {
        return ArgumentMismatch(name + " was given a disallowed flag override");
    }
    static ArgumentMismatch PartialType(std::string name, int num, std::string type) {
        return ArgumentMismatch(name + ": " + type + " only partially specified: " + std::to_string(num) +
                                " required for each element");
    }
};

class RequiresError : public ParseError {
    CLI11_ERROR_DEF(ParseError, RequiresError)
    RequiresError(std::string curname, std::string subname)
        : RequiresError(curname + " requires " + subname, ExitCodes::RequiresError) {}
};

class ExcludesError : public ParseError {
    CLI11_ERROR_DEF(ParseError, ExcludesError)
    ExcludesError(std::string curname, std::string subname)
        : ExcludesError(curname + " excludes " + subname, ExitCodes::ExcludesError) {}
};

class ExtrasError : public ParseError {
    CLI11_ERROR_DEF(ParseError, ExtrasError)
    explicit ExtrasError(std::vector<std::string> args)
        : ExtrasError((args.size() > 1 ? "The following arguments were not expected: "
                                       : "The following argument was not expected: ") +
                          detail::rjoin(args, " "),
                      ExitCodes::ExtrasError) {}
    ExtrasError(const std::string &name, std::vector<std::string> args)
        : ExtrasError(name,
                      (args.size() > 1 ? "The following arguments were not expected: "
                                       : "The following argument was not expected: ") +
                          detail::rjoin(args, " "),
                      ExitCodes::ExtrasError) {}
};

class ConfigError : public ParseError {
    CLI11_ERROR_DEF(ParseError, ConfigError)
    CLI11_ERROR_SIMPLE(ConfigError)
    static ConfigError Extras(std::string item) { return ConfigError("INI was not able to parse " + item); }
    static ConfigError NotConfigurable(std::string item) {
        return ConfigError(item + ": This option is not allowed in a configuration file");
    }
};

class InvalidError : public ParseError {
    CLI11_ERROR_DEF(ParseError, InvalidError)
    explicit InvalidError(std::string name)
        : InvalidError(name + ": Too many positional arguments with unlimited expected args", ExitCodes::InvalidError) {
    }
};

class HorribleError : public ParseError {
    CLI11_ERROR_DEF(ParseError, HorribleError)
    CLI11_ERROR_SIMPLE(HorribleError)
};

// After parsing

class OptionNotFound : public Error {
    CLI11_ERROR_DEF(Error, OptionNotFound)
    explicit OptionNotFound(std::string name) : OptionNotFound(name + " not found", ExitCodes::OptionNotFound) {}
};

#undef CLI11_ERROR_DEF
#undef CLI11_ERROR_SIMPLE





// Type tools

// Utilities for type enabling
namespace detail {
// Based generally on https://rmf.io/cxx11/almost-static-if
enum class enabler {};

constexpr enabler dummy = {};
}  // namespace detail

template <bool B, class T = void> using enable_if_t = typename std::enable_if<B, T>::type;

template <typename... Ts> struct make_void { using type = void; };

template <typename... Ts> using void_t = typename make_void<Ts...>::type;

template <bool B, class T, class F> using conditional_t = typename std::conditional<B, T, F>::type;

template <typename T> struct is_bool : std::false_type {};

template <> struct is_bool<bool> : std::true_type {};

template <typename T> struct is_shared_ptr : std::false_type {};

template <typename T> struct is_shared_ptr<std::shared_ptr<T>> : std::true_type {};

template <typename T> struct is_shared_ptr<const std::shared_ptr<T>> : std::true_type {};

template <typename T> struct is_copyable_ptr {
    static bool const value = is_shared_ptr<T>::value || std::is_pointer<T>::value;
};

template <typename T> struct IsMemberType { using type = T; };

template <> struct IsMemberType<const char *> { using type = std::string; };

namespace detail {

// These are utilities for IsMember and other transforming objects


template <typename T, typename Enable = void> struct element_type { using type = T; };

template <typename T> struct element_type<T, typename std::enable_if<is_copyable_ptr<T>::value>::type> {
    using type = typename std::pointer_traits<T>::element_type;
};

template <typename T> struct element_value_type { using type = typename element_type<T>::type::value_type; };

template <typename T, typename _ = void> struct pair_adaptor : std::false_type {
    using value_type = typename T::value_type;
    using first_type = typename std::remove_const<value_type>::type;
    using second_type = typename std::remove_const<value_type>::type;

    template <typename Q> static auto first(Q &&pair_value) -> decltype(std::forward<Q>(pair_value)) {
        return std::forward<Q>(pair_value);
    }
    template <typename Q> static auto second(Q &&pair_value) -> decltype(std::forward<Q>(pair_value)) {
        return std::forward<Q>(pair_value);
    }
};

template <typename T>
struct pair_adaptor<
    T,
    conditional_t<false, void_t<typename T::value_type::first_type, typename T::value_type::second_type>, void>>
    : std::true_type {
    using value_type = typename T::value_type;
    using first_type = typename std::remove_const<typename value_type::first_type>::type;
    using second_type = typename std::remove_const<typename value_type::second_type>::type;

    template <typename Q> static auto first(Q &&pair_value) -> decltype(std::get<0>(std::forward<Q>(pair_value))) {
        return std::get<0>(std::forward<Q>(pair_value));
    }
    template <typename Q> static auto second(Q &&pair_value) -> decltype(std::get<1>(std::forward<Q>(pair_value))) {
        return std::get<1>(std::forward<Q>(pair_value));
    }
};

// Warning is suppressed due to "bug" in gcc<5.0 and gcc 7.0 with c++17 enabled that generates a Wnarrowing warning
// in the unevaluated context even if the function that was using this wasn't used.  The standard says narrowing in
// brace initialization shouldn't be allowed but for backwards compatibility gcc allows it in some contexts.  It is a
// little fuzzy what happens in template constructs and I think that was something GCC took a little while to work out.
// But regardless some versions of gcc generate a warning when they shouldn't from the following code so that should be
// suppressed
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wnarrowing"
#endif
// check for constructibility from a specific type and copy assignable used in the parse detection
template <typename T, typename C> class is_direct_constructible {
    template <typename TT, typename CC>
    static auto test(int, std::true_type) -> decltype(
// NVCC warns about narrowing conversions here
#ifdef __CUDACC__
#pragma diag_suppress 2361
#endif
        TT{std::declval<CC>()}
#ifdef __CUDACC__
#pragma diag_default 2361
#endif
        ,
        std::is_move_assignable<TT>());

    template <typename TT, typename CC> static auto test(int, std::false_type) -> std::false_type;

    template <typename, typename> static auto test(...) -> std::false_type;

  public:
    static constexpr bool value = decltype(test<T, C>(0, typename std::is_constructible<T, C>::type()))::value;
};
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif

// Check for output streamability
// Based on https://stackoverflow.com/questions/22758291/how-can-i-detect-if-a-type-can-be-streamed-to-an-stdostream

template <typename T, typename S = std::ostringstream> class is_ostreamable {
    template <typename TT, typename SS>
    static auto test(int) -> decltype(std::declval<SS &>() << std::declval<TT>(), std::true_type());

    template <typename, typename> static auto test(...) -> std::false_type;

  public:
    static constexpr bool value = decltype(test<T, S>(0))::value;
};

template <typename T, typename S = std::istringstream> class is_istreamable {
    template <typename TT, typename SS>
    static auto test(int) -> decltype(std::declval<SS &>() >> std::declval<TT &>(), std::true_type());

    template <typename, typename> static auto test(...) -> std::false_type;

  public:
    static constexpr bool value = decltype(test<T, S>(0))::value;
};

template <typename T> class is_complex {
    template <typename TT>
    static auto test(int) -> decltype(std::declval<TT>().real(), std::declval<TT>().imag(), std::true_type());

    template <typename> static auto test(...) -> std::false_type;

  public:
    static constexpr bool value = decltype(test<T>(0))::value;
};

template <typename T, enable_if_t<is_istreamable<T>::value, detail::enabler> = detail::dummy>
bool from_stream(const std::string &istring, T &obj) {
    std::istringstream is;
    is.str(istring);
    is >> obj;
    return !is.fail() && !is.rdbuf()->in_avail();
}

template <typename T, enable_if_t<!is_istreamable<T>::value, detail::enabler> = detail::dummy>
bool from_stream(const std::string & /*istring*/, T & /*obj*/) {
    return false;
}

// check to see if an object is a mutable container (fail by default)
template <typename T, typename _ = void> struct is_mutable_container : std::false_type {};

template <typename T>
struct is_mutable_container<
    T,
    conditional_t<false,
                  void_t<typename T::value_type,
                         decltype(std::declval<T>().end()),
                         decltype(std::declval<T>().clear()),
                         decltype(std::declval<T>().insert(std::declval<decltype(std::declval<T>().end())>(),
                                                           std::declval<const typename T::value_type &>()))>,
                  void>>
    : public conditional_t<std::is_constructible<T, std::string>::value, std::false_type, std::true_type> {};

// check to see if an object is a mutable container (fail by default)
template <typename T, typename _ = void> struct is_readable_container : std::false_type {};

template <typename T>
struct is_readable_container<
    T,
    conditional_t<false, void_t<decltype(std::declval<T>().end()), decltype(std::declval<T>().begin())>, void>>
    : public std::true_type {};

// check to see if an object is a wrapper (fail by default)
template <typename T, typename _ = void> struct is_wrapper : std::false_type {};

// check if an object is a wrapper (it has a value_type defined)
template <typename T>
struct is_wrapper<T, conditional_t<false, void_t<typename T::value_type>, void>> : public std::true_type {};

// Check for tuple like types, as in classes with a tuple_size type trait
template <typename S> class is_tuple_like {
    template <typename SS>
    // static auto test(int)
    //     -> decltype(std::conditional<(std::tuple_size<SS>::value > 0), std::true_type, std::false_type>::type());
    static auto test(int) -> decltype(std::tuple_size<typename std::decay<SS>::type>::value, std::true_type{});
    template <typename> static auto test(...) -> std::false_type;

  public:
    static constexpr bool value = decltype(test<S>(0))::value;
};

template <typename T, enable_if_t<std::is_convertible<T, std::string>::value, detail::enabler> = detail::dummy>
auto to_string(T &&value) -> decltype(std::forward<T>(value)) {
    return std::forward<T>(value);
}

template <typename T,
          enable_if_t<std::is_constructible<std::string, T>::value && !std::is_convertible<T, std::string>::value,
                      detail::enabler> = detail::dummy>
std::string to_string(const T &value) {
    return std::string(value);  // NOLINT(google-readability-casting)
}

template <typename T,
          enable_if_t<!std::is_convertible<std::string, T>::value && !std::is_constructible<std::string, T>::value &&
                          is_ostreamable<T>::value,
                      detail::enabler> = detail::dummy>
std::string to_string(T &&value) {
    std::stringstream stream;
    stream << value;
    return stream.str();
}

template <typename T,
          enable_if_t<!std::is_constructible<std::string, T>::value && !is_ostreamable<T>::value &&
                          !is_readable_container<typename std::remove_const<T>::type>::value,
                      detail::enabler> = detail::dummy>
std::string to_string(T &&) {
    return {};
}

template <typename T,
          enable_if_t<!std::is_constructible<std::string, T>::value && !is_ostreamable<T>::value &&
                          is_readable_container<T>::value,
                      detail::enabler> = detail::dummy>
std::string to_string(T &&variable) {
    auto cval = variable.begin();
    auto end = variable.end();
    if(cval == end) {
        return {"{}"};
    }
    std::vector<std::string> defaults;
    while(cval != end) {
        defaults.emplace_back(CLI::detail::to_string(*cval));
        ++cval;
    }
    return {"[" + detail::join(defaults) + "]"};
}

template <typename T1,
          typename T2,
          typename T,
          enable_if_t<std::is_same<T1, T2>::value, detail::enabler> = detail::dummy>
auto checked_to_string(T &&value) -> decltype(to_string(std::forward<T>(value))) {
    return to_string(std::forward<T>(value));
}

template <typename T1,
          typename T2,
          typename T,
          enable_if_t<!std::is_same<T1, T2>::value, detail::enabler> = detail::dummy>
std::string checked_to_string(T &&) {
    return std::string{};
}
template <typename T, enable_if_t<std::is_arithmetic<T>::value, detail::enabler> = detail::dummy>
std::string value_string(const T &value) {
    return std::to_string(value);
}
template <typename T, enable_if_t<std::is_enum<T>::value, detail::enabler> = detail::dummy>
std::string value_string(const T &value) {
    return std::to_string(static_cast<typename std::underlying_type<T>::type>(value));
}
template <typename T,
          enable_if_t<!std::is_enum<T>::value && !std::is_arithmetic<T>::value, detail::enabler> = detail::dummy>
auto value_string(const T &value) -> decltype(to_string(value)) {
    return to_string(value);
}

template <typename T, typename def, typename Enable = void> struct wrapped_type { using type = def; };

template <typename T, typename def> struct wrapped_type<T, def, typename std::enable_if<is_wrapper<T>::value>::type> {
    using type = typename T::value_type;
};

template <typename T, typename Enable = void> struct type_count_base { static const int value{0}; };

template <typename T>
struct type_count_base<T,
                       typename std::enable_if<!is_tuple_like<T>::value && !is_mutable_container<T>::value &&
                                               !std::is_void<T>::value>::type> {
    static constexpr int value{1};
};

template <typename T>
struct type_count_base<T, typename std::enable_if<is_tuple_like<T>::value && !is_mutable_container<T>::value>::type> {
    static constexpr int value{std::tuple_size<T>::value};
};

template <typename T> struct type_count_base<T, typename std::enable_if<is_mutable_container<T>::value>::type> {
    static constexpr int value{type_count_base<typename T::value_type>::value};
};


template <typename T> struct subtype_count;

template <typename T> struct subtype_count_min;

template <typename T, typename Enable = void> struct type_count { static const int value{0}; };

template <typename T>
struct type_count<T,
                  typename std::enable_if<!is_wrapper<T>::value && !is_tuple_like<T>::value && !is_complex<T>::value &&
                                          !std::is_void<T>::value>::type> {
    static constexpr int value{1};
};

template <typename T> struct type_count<T, typename std::enable_if<is_complex<T>::value>::type> {
    static constexpr int value{2};
};

template <typename T> struct type_count<T, typename std::enable_if<is_mutable_container<T>::value>::type> {
    static constexpr int value{subtype_count<typename T::value_type>::value};
};

template <typename T>
struct type_count<T,
                  typename std::enable_if<is_wrapper<T>::value && !is_complex<T>::value && !is_tuple_like<T>::value &&
                                          !is_mutable_container<T>::value>::type> {
    static constexpr int value{type_count<typename T::value_type>::value};
};

template <typename T, std::size_t I>
constexpr typename std::enable_if<I == type_count_base<T>::value, int>::type tuple_type_size() {
    return 0;
}

template <typename T, std::size_t I>
    constexpr typename std::enable_if < I<type_count_base<T>::value, int>::type tuple_type_size() {
    return subtype_count<typename std::tuple_element<I, T>::type>::value + tuple_type_size<T, I + 1>();
}

template <typename T> struct type_count<T, typename std::enable_if<is_tuple_like<T>::value>::type> {
    static constexpr int value{tuple_type_size<T, 0>()};
};

template <typename T> struct subtype_count {
    static constexpr int value{is_mutable_container<T>::value ? expected_max_vector_size : type_count<T>::value};
};

template <typename T, typename Enable = void> struct type_count_min { static const int value{0}; };

template <typename T>
struct type_count_min<
    T,
    typename std::enable_if<!is_mutable_container<T>::value && !is_tuple_like<T>::value && !is_wrapper<T>::value &&
                            !is_complex<T>::value && !std::is_void<T>::value>::type> {
    static constexpr int value{type_count<T>::value};
};

template <typename T> struct type_count_min<T, typename std::enable_if<is_complex<T>::value>::type> {
    static constexpr int value{1};
};

template <typename T>
struct type_count_min<
    T,
    typename std::enable_if<is_wrapper<T>::value && !is_complex<T>::value && !is_tuple_like<T>::value>::type> {
    static constexpr int value{subtype_count_min<typename T::value_type>::value};
};

template <typename T, std::size_t I>
constexpr typename std::enable_if<I == type_count_base<T>::value, int>::type tuple_type_size_min() {
    return 0;
}

template <typename T, std::size_t I>
    constexpr typename std::enable_if < I<type_count_base<T>::value, int>::type tuple_type_size_min() {
    return subtype_count_min<typename std::tuple_element<I, T>::type>::value + tuple_type_size_min<T, I + 1>();
}

template <typename T> struct type_count_min<T, typename std::enable_if<is_tuple_like<T>::value>::type> {
    static constexpr int value{tuple_type_size_min<T, 0>()};
};

template <typename T> struct subtype_count_min {
    static constexpr int value{is_mutable_container<T>::value
                                   ? ((type_count<T>::value < expected_max_vector_size) ? type_count<T>::value : 0)
                                   : type_count_min<T>::value};
};

template <typename T, typename Enable = void> struct expected_count { static const int value{0}; };

template <typename T>
struct expected_count<T,
                      typename std::enable_if<!is_mutable_container<T>::value && !is_wrapper<T>::value &&
                                              !std::is_void<T>::value>::type> {
    static constexpr int value{1};
};
template <typename T> struct expected_count<T, typename std::enable_if<is_mutable_container<T>::value>::type> {
    static constexpr int value{expected_max_vector_size};
};

template <typename T>
struct expected_count<T, typename std::enable_if<!is_mutable_container<T>::value && is_wrapper<T>::value>::type> {
    static constexpr int value{expected_count<typename T::value_type>::value};
};

// Enumeration of the different supported categorizations of objects
enum class object_category : int {
    char_value = 1,
    integral_value = 2,
    unsigned_integral = 4,
    enumeration = 6,
    boolean_value = 8,
    floating_point = 10,
    number_constructible = 12,
    double_constructible = 14,
    integer_constructible = 16,
    // string like types
    string_assignable = 23,
    string_constructible = 24,
    other = 45,
    // special wrapper or container types
    wrapper_value = 50,
    complex_number = 60,
    tuple_value = 70,
    container_value = 80,

};


template <typename T, typename Enable = void> struct classify_object {
    static constexpr object_category value{object_category::other};
};

template <typename T>
struct classify_object<
    T,
    typename std::enable_if<std::is_integral<T>::value && !std::is_same<T, char>::value && std::is_signed<T>::value &&
                            !is_bool<T>::value && !std::is_enum<T>::value>::type> {
    static constexpr object_category value{object_category::integral_value};
};

template <typename T>
struct classify_object<T,
                       typename std::enable_if<std::is_integral<T>::value && std::is_unsigned<T>::value &&
                                               !std::is_same<T, char>::value && !is_bool<T>::value>::type> {
    static constexpr object_category value{object_category::unsigned_integral};
};

template <typename T>
struct classify_object<T, typename std::enable_if<std::is_same<T, char>::value && !std::is_enum<T>::value>::type> {
    static constexpr object_category value{object_category::char_value};
};

template <typename T> struct classify_object<T, typename std::enable_if<is_bool<T>::value>::type> {
    static constexpr object_category value{object_category::boolean_value};
};

template <typename T> struct classify_object<T, typename std::enable_if<std::is_floating_point<T>::value>::type> {
    static constexpr object_category value{object_category::floating_point};
};

template <typename T>
struct classify_object<T,
                       typename std::enable_if<!std::is_floating_point<T>::value && !std::is_integral<T>::value &&
                                               std::is_assignable<T &, std::string>::value>::type> {
    static constexpr object_category value{object_category::string_assignable};
};

template <typename T>
struct classify_object<
    T,
    typename std::enable_if<!std::is_floating_point<T>::value && !std::is_integral<T>::value &&
                            !std::is_assignable<T &, std::string>::value && (type_count<T>::value == 1) &&
                            std::is_constructible<T, std::string>::value>::type> {
    static constexpr object_category value{object_category::string_constructible};
};

template <typename T> struct classify_object<T, typename std::enable_if<std::is_enum<T>::value>::type> {
    static constexpr object_category value{object_category::enumeration};
};

template <typename T> struct classify_object<T, typename std::enable_if<is_complex<T>::value>::type> {
    static constexpr object_category value{object_category::complex_number};
};

template <typename T> struct uncommon_type {
    using type = typename std::conditional<!std::is_floating_point<T>::value && !std::is_integral<T>::value &&
                                               !std::is_assignable<T &, std::string>::value &&
                                               !std::is_constructible<T, std::string>::value && !is_complex<T>::value &&
                                               !is_mutable_container<T>::value && !std::is_enum<T>::value,
                                           std::true_type,
                                           std::false_type>::type;
    static constexpr bool value = type::value;
};

template <typename T>
struct classify_object<T,
                       typename std::enable_if<(!is_mutable_container<T>::value && is_wrapper<T>::value &&
                                                !is_tuple_like<T>::value && uncommon_type<T>::value)>::type> {
    static constexpr object_category value{object_category::wrapper_value};
};

template <typename T>
struct classify_object<T,
                       typename std::enable_if<uncommon_type<T>::value && type_count<T>::value == 1 &&
                                               !is_wrapper<T>::value && is_direct_constructible<T, double>::value &&
                                               is_direct_constructible<T, int>::value>::type> {
    static constexpr object_category value{object_category::number_constructible};
};

template <typename T>
struct classify_object<T,
                       typename std::enable_if<uncommon_type<T>::value && type_count<T>::value == 1 &&
                                               !is_wrapper<T>::value && !is_direct_constructible<T, double>::value &&
                                               is_direct_constructible<T, int>::value>::type> {
    static constexpr object_category value{object_category::integer_constructible};
};

template <typename T>
struct classify_object<T,
                       typename std::enable_if<uncommon_type<T>::value && type_count<T>::value == 1 &&
                                               !is_wrapper<T>::value && is_direct_constructible<T, double>::value &&
                                               !is_direct_constructible<T, int>::value>::type> {
    static constexpr object_category value{object_category::double_constructible};
};

template <typename T>
struct classify_object<
    T,
    typename std::enable_if<is_tuple_like<T>::value &&
                            ((type_count<T>::value >= 2 && !is_wrapper<T>::value) ||
                             (uncommon_type<T>::value && !is_direct_constructible<T, double>::value &&
                              !is_direct_constructible<T, int>::value) ||
                             (uncommon_type<T>::value && type_count<T>::value >= 2))>::type> {
    static constexpr object_category value{object_category::tuple_value};
    // the condition on this class requires it be like a tuple, but on some compilers (like Xcode) tuples can be
    // constructed from just the first element so tuples of <string, int,int> can be constructed from a string, which
    // could lead to issues so there are two variants of the condition, the first isolates things with a type size >=2
    // mainly to get tuples on Xcode with the exception of wrappers, the second is the main one and just separating out
    // those cases that are caught by other object classifications
};

template <typename T> struct classify_object<T, typename std::enable_if<is_mutable_container<T>::value>::type> {
    static constexpr object_category value{object_category::container_value};
};

// Type name print


template <typename T,
          enable_if_t<classify_object<T>::value == object_category::char_value, detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "CHAR";
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::integral_value ||
                          classify_object<T>::value == object_category::integer_constructible,
                      detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "INT";
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::unsigned_integral, detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "UINT";
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::floating_point ||
                          classify_object<T>::value == object_category::number_constructible ||
                          classify_object<T>::value == object_category::double_constructible,
                      detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "FLOAT";
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::enumeration, detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "ENUM";
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::boolean_value, detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "BOOLEAN";
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::complex_number, detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "COMPLEX";
}

template <typename T,
          enable_if_t<classify_object<T>::value >= object_category::string_assignable &&
                          classify_object<T>::value <= object_category::other,
                      detail::enabler> = detail::dummy>
constexpr const char *type_name() {
    return "TEXT";
}
template <typename T,
          enable_if_t<classify_object<T>::value == object_category::tuple_value && type_count_base<T>::value >= 2,
                      detail::enabler> = detail::dummy>
std::string type_name();  // forward declaration

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::container_value ||
                          classify_object<T>::value == object_category::wrapper_value,
                      detail::enabler> = detail::dummy>
std::string type_name();  // forward declaration

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::tuple_value && type_count_base<T>::value == 1,
                      detail::enabler> = detail::dummy>
inline std::string type_name() {
    return type_name<typename std::decay<typename std::tuple_element<0, T>::type>::type>();
}

template <typename T, std::size_t I>
inline typename std::enable_if<I == type_count_base<T>::value, std::string>::type tuple_name() {
    return std::string{};
}

template <typename T, std::size_t I>
inline typename std::enable_if<(I < type_count_base<T>::value), std::string>::type tuple_name() {
    auto str = std::string{type_name<typename std::decay<typename std::tuple_element<I, T>::type>::type>()} + ',' +
               tuple_name<T, I + 1>();
    if(str.back() == ',')
        str.pop_back();
    return str;
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::tuple_value && type_count_base<T>::value >= 2,
                      detail::enabler>>
inline std::string type_name() {
    auto tname = std::string(1, '[') + tuple_name<T, 0>();
    tname.push_back(']');
    return tname;
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::container_value ||
                          classify_object<T>::value == object_category::wrapper_value,
                      detail::enabler>>
inline std::string type_name() {
    return type_name<typename T::value_type>();
}

// Lexical cast

template <typename T, enable_if_t<std::is_unsigned<T>::value, detail::enabler> = detail::dummy>
bool integral_conversion(const std::string &input, T &output) noexcept {
    if(input.empty()) {
        return false;
    }
    char *val = nullptr;
    std::uint64_t output_ll = std::strtoull(input.c_str(), &val, 0);
    output = static_cast<T>(output_ll);
    if(val == (input.c_str() + input.size()) && static_cast<std::uint64_t>(output) == output_ll) {
        return true;
    }
    val = nullptr;
    std::int64_t output_sll = std::strtoll(input.c_str(), &val, 0);
    if(val == (input.c_str() + input.size())) {
        output = (output_sll < 0) ? static_cast<T>(0) : static_cast<T>(output_sll);
        return (static_cast<std::int64_t>(output) == output_sll);
    }
    return false;
}

template <typename T, enable_if_t<std::is_signed<T>::value, detail::enabler> = detail::dummy>
bool integral_conversion(const std::string &input, T &output) noexcept {
    if(input.empty()) {
        return false;
    }
    char *val = nullptr;
    std::int64_t output_ll = std::strtoll(input.c_str(), &val, 0);
    output = static_cast<T>(output_ll);
    if(val == (input.c_str() + input.size()) && static_cast<std::int64_t>(output) == output_ll) {
        return true;
    }
    if(input == "true") {
        // this is to deal with a few oddities with flags and wrapper int types
        output = static_cast<T>(1);
        return true;
    }
    return false;
}

inline std::int64_t to_flag_value(std::string val) {
    static const std::string trueString("true");
    static const std::string falseString("false");
    if(val == trueString) {
        return 1;
    }
    if(val == falseString) {
        return -1;
    }
    val = detail::to_lower(val);
    std::int64_t ret = 0;
    if(val.size() == 1) {
        if(val[0] >= '1' && val[0] <= '9') {
            return (static_cast<std::int64_t>(val[0]) - '0');
        }
        switch(val[0]) {
        case '0':
        case 'f':
        case 'n':
        case '-':
            ret = -1;
            break;
        case 't':
        case 'y':
        case '+':
            ret = 1;
            break;
        default:
            throw std::invalid_argument("unrecognized character");
        }
        return ret;
    }
    if(val == trueString || val == "on" || val == "yes" || val == "enable") {
        ret = 1;
    } else if(val == falseString || val == "off" || val == "no" || val == "disable") {
        ret = -1;
    } else {
        ret = std::stoll(val);
    }
    return ret;
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::integral_value ||
                          classify_object<T>::value == object_category::unsigned_integral,
                      detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    return integral_conversion(input, output);
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::char_value, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    if(input.size() == 1) {
        output = static_cast<T>(input[0]);
        return true;
    }
    return integral_conversion(input, output);
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::boolean_value, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    try {
        auto out = to_flag_value(input);
        output = (out > 0);
        return true;
    } catch(const std::invalid_argument &) {
        return false;
    } catch(const std::out_of_range &) {
        // if the number is out of the range of a 64 bit value then it is still a number and for this purpose is still
        // valid all we care about the sign
        output = (input[0] != '-');
        return true;
    }
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::floating_point, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    if(input.empty()) {
        return false;
    }
    char *val = nullptr;
    auto output_ld = std::strtold(input.c_str(), &val);
    output = static_cast<T>(output_ld);
    return val == (input.c_str() + input.size());
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::complex_number, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    using XC = typename wrapped_type<T, double>::type;
    XC x{0.0}, y{0.0};
    auto str1 = input;
    bool worked = false;
    auto nloc = str1.find_last_of("+-");
    if(nloc != std::string::npos && nloc > 0) {
        worked = detail::lexical_cast(str1.substr(0, nloc), x);
        str1 = str1.substr(nloc);
        if(str1.back() == 'i' || str1.back() == 'j')
            str1.pop_back();
        worked = worked && detail::lexical_cast(str1, y);
    } else {
        if(str1.back() == 'i' || str1.back() == 'j') {
            str1.pop_back();
            worked = detail::lexical_cast(str1, y);
            x = XC{0};
        } else {
            worked = detail::lexical_cast(str1, x);
            y = XC{0};
        }
    }
    if(worked) {
        output = T{x, y};
        return worked;
    }
    return from_stream(input, output);
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::string_assignable, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    output = input;
    return true;
}

template <
    typename T,
    enable_if_t<classify_object<T>::value == object_category::string_constructible, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    output = T(input);
    return true;
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::enumeration, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    typename std::underlying_type<T>::type val;
    if(!integral_conversion(input, val)) {
        return false;
    }
    output = static_cast<T>(val);
    return true;
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::wrapper_value &&
                          std::is_assignable<T &, typename T::value_type>::value,
                      detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    typename T::value_type val;
    if(lexical_cast(input, val)) {
        output = val;
        return true;
    }
    return from_stream(input, output);
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::wrapper_value &&
                          !std::is_assignable<T &, typename T::value_type>::value && std::is_assignable<T &, T>::value,
                      detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    typename T::value_type val;
    if(lexical_cast(input, val)) {
        output = T{val};
        return true;
    }
    return from_stream(input, output);
}

template <
    typename T,
    enable_if_t<classify_object<T>::value == object_category::number_constructible, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    int val = 0;
    if(integral_conversion(input, val)) {
        output = T(val);
        return true;
    }

    double dval = 0.0;
    if(lexical_cast(input, dval)) {
        output = T{dval};
        return true;
    }

    return from_stream(input, output);
}

template <
    typename T,
    enable_if_t<classify_object<T>::value == object_category::integer_constructible, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    int val = 0;
    if(integral_conversion(input, val)) {
        output = T(val);
        return true;
    }
    return from_stream(input, output);
}

template <
    typename T,
    enable_if_t<classify_object<T>::value == object_category::double_constructible, detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    double val = 0.0;
    if(lexical_cast(input, val)) {
        output = T{val};
        return true;
    }
    return from_stream(input, output);
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::other && std::is_assignable<T &, int>::value,
                      detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    int val = 0;
    if(integral_conversion(input, val)) {
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4800)
#endif
        // with Atomic<XX> this could produce a warning due to the conversion but if atomic gets here it is an old style
        // so will most likely still work
        output = val;
#ifdef _MSC_VER
#pragma warning(pop)
#endif
        return true;
    }
    // LCOV_EXCL_START
    // This version of cast is only used for odd cases in an older compilers the fail over
    // from_stream is tested elsewhere an not relevant for coverage here
    return from_stream(input, output);
    // LCOV_EXCL_STOP
}

template <typename T,
          enable_if_t<classify_object<T>::value == object_category::other && !std::is_assignable<T &, int>::value,
                      detail::enabler> = detail::dummy>
bool lexical_cast(const std::string &input, T &output) {
    static_assert(is_istreamable<T>::value,
                  "option object type must have a lexical cast overload or streaming input operator(>>) defined, if it "
                  "is convertible from another type use the add_option<T, XC>(...) with XC being the known type");
    return from_stream(input, output);
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<std::is_same<AssignTo, ConvertTo>::value &&
                          (classify_object<AssignTo>::value == object_category::string_assignable ||
                           classify_object<AssignTo>::value == object_category::string_constructible),
                      detail::enabler> = detail::dummy>
bool lexical_assign(const std::string &input, AssignTo &output) {
    return lexical_cast(input, output);
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<std::is_same<AssignTo, ConvertTo>::value && std::is_assignable<AssignTo &, AssignTo>::value &&
                          classify_object<AssignTo>::value != object_category::string_assignable &&
                          classify_object<AssignTo>::value != object_category::string_constructible,
                      detail::enabler> = detail::dummy>
bool lexical_assign(const std::string &input, AssignTo &output) {
    if(input.empty()) {
        output = AssignTo{};
        return true;
    }

    return lexical_cast(input, output);
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<std::is_same<AssignTo, ConvertTo>::value && !std::is_assignable<AssignTo &, AssignTo>::value &&
                          classify_object<AssignTo>::value == object_category::wrapper_value,
                      detail::enabler> = detail::dummy>
bool lexical_assign(const std::string &input, AssignTo &output) {
    if(input.empty()) {
        typename AssignTo::value_type emptyVal{};
        output = emptyVal;
        return true;
    }
    return lexical_cast(input, output);
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<std::is_same<AssignTo, ConvertTo>::value && !std::is_assignable<AssignTo &, AssignTo>::value &&
                          classify_object<AssignTo>::value != object_category::wrapper_value &&
                          std::is_assignable<AssignTo &, int>::value,
                      detail::enabler> = detail::dummy>
bool lexical_assign(const std::string &input, AssignTo &output) {
    if(input.empty()) {
        output = 0;
        return true;
    }
    int val = 0;
    if(lexical_cast(input, val)) {
        output = val;
        return true;
    }
    return false;
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<!std::is_same<AssignTo, ConvertTo>::value && std::is_assignable<AssignTo &, ConvertTo &>::value,
                      detail::enabler> = detail::dummy>
bool lexical_assign(const std::string &input, AssignTo &output) {
    ConvertTo val{};
    bool parse_result = (!input.empty()) ? lexical_cast<ConvertTo>(input, val) : true;
    if(parse_result) {
        output = val;
    }
    return parse_result;
}

template <
    typename AssignTo,
    typename ConvertTo,
    enable_if_t<!std::is_same<AssignTo, ConvertTo>::value && !std::is_assignable<AssignTo &, ConvertTo &>::value &&
                    std::is_move_assignable<AssignTo>::value,
                detail::enabler> = detail::dummy>
bool lexical_assign(const std::string &input, AssignTo &output) {
    ConvertTo val{};
    bool parse_result = input.empty() ? true : lexical_cast<ConvertTo>(input, val);
    if(parse_result) {
        output = AssignTo(val);  // use () form of constructor to allow some implicit conversions
    }
    return parse_result;
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<classify_object<ConvertTo>::value <= object_category::other &&
                          classify_object<AssignTo>::value <= object_category::wrapper_value,
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {
    return lexical_assign<AssignTo, ConvertTo>(strings[0], output);
}

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<(type_count<AssignTo>::value <= 2) && expected_count<AssignTo>::value == 1 &&
                          is_tuple_like<ConvertTo>::value && type_count_base<ConvertTo>::value == 2,
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {
    // the remove const is to handle pair types coming from a container
    typename std::remove_const<typename std::tuple_element<0, ConvertTo>::type>::type v1;
    typename std::tuple_element<1, ConvertTo>::type v2;
    bool retval = lexical_assign<decltype(v1), decltype(v1)>(strings[0], v1);
    if(strings.size() > 1) {
        retval = retval && lexical_assign<decltype(v2), decltype(v2)>(strings[1], v2);
    }
    if(retval) {
        output = AssignTo{v1, v2};
    }
    return retval;
}

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_mutable_container<AssignTo>::value && is_mutable_container<ConvertTo>::value &&
                          type_count<ConvertTo>::value == 1,
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {
    output.erase(output.begin(), output.end());
    if(strings.size() == 1 && strings[0] == "{}") {
        return true;
    }
    bool skip_remaining = false;
    if(strings.size() == 2 && strings[0] == "{}" && is_separator(strings[1])) {
        skip_remaining = true;
    }
    for(const auto &elem : strings) {
        typename AssignTo::value_type out;
        bool retval = lexical_assign<typename AssignTo::value_type, typename ConvertTo::value_type>(elem, out);
        if(!retval) {
            return false;
        }
        output.insert(output.end(), std::move(out));
        if(skip_remaining) {
            break;
        }
    }
    return (!output.empty());
}

template <class AssignTo, class ConvertTo, enable_if_t<is_complex<ConvertTo>::value, detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std::string> &strings, AssignTo &output) {

    if(strings.size() >= 2 && !strings[1].empty()) {
        using XC2 = typename wrapped_type<ConvertTo, double>::type;
        XC2 x{0.0}, y{0.0};
        auto str1 = strings[1];
        if(str1.back() == 'i' || str1.back() == 'j') {
            str1.pop_back();
        }
        auto worked = detail::lexical_cast(strings[0], x) && detail::lexical_cast(str1, y);
        if(worked) {
            output = ConvertTo{x, y};
        }
        return worked;
    }
    return lexical_assign<AssignTo, ConvertTo>(strings[0], output);
}

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_mutable_container<AssignTo>::value && (expected_count<ConvertTo>::value == 1) &&
                          (type_count<ConvertTo>::value == 1),
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {
    bool retval = true;
    output.clear();
    output.reserve(strings.size());
    for(const auto &elem : strings) {

        output.emplace_back();
        retval = retval && lexical_assign<typename AssignTo::value_type, ConvertTo>(elem, output.back());
    }
    return (!output.empty()) && retval;
}

// forward declaration

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_mutable_container<AssignTo>::value && is_mutable_container<ConvertTo>::value &&
                          type_count_base<ConvertTo>::value == 2,
                      detail::enabler> = detail::dummy>
bool lexical_conversion(std::vector<std::string> strings, AssignTo &output);

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_mutable_container<AssignTo>::value && is_mutable_container<ConvertTo>::value &&
                          type_count_base<ConvertTo>::value != 2 &&
                          ((type_count<ConvertTo>::value > 2) ||
                           (type_count<ConvertTo>::value > type_count_base<ConvertTo>::value)),
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std::string> &strings, AssignTo &output);

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_tuple_like<AssignTo>::value && is_tuple_like<ConvertTo>::value &&
                          (type_count_base<ConvertTo>::value != type_count<ConvertTo>::value ||
                           type_count<ConvertTo>::value > 2),
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std::string> &strings, AssignTo &output);  // forward declaration

template <typename AssignTo,
          typename ConvertTo,
          enable_if_t<!is_tuple_like<AssignTo>::value && !is_mutable_container<AssignTo>::value &&
                          classify_object<ConvertTo>::value != object_category::wrapper_value &&
                          (is_mutable_container<ConvertTo>::value || type_count<ConvertTo>::value > 2),
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {

    if(strings.size() > 1 || (!strings.empty() && !(strings.front().empty()))) {
        ConvertTo val;
        auto retval = lexical_conversion<ConvertTo, ConvertTo>(strings, val);
        output = AssignTo{val};
        return retval;
    }
    output = AssignTo{};
    return true;
}

template <class AssignTo, class ConvertTo, std::size_t I>
inline typename std::enable_if<(I >= type_count_base<AssignTo>::value), bool>::type
tuple_conversion(const std::vector<std::string> &, AssignTo &) {
    return true;
}

template <class AssignTo, class ConvertTo>
inline typename std::enable_if<!is_mutable_container<ConvertTo>::value && type_count<ConvertTo>::value == 1, bool>::type
tuple_type_conversion(std::vector<std::string> &strings, AssignTo &output) {
    auto retval = lexical_assign<AssignTo, ConvertTo>(strings[0], output);
    strings.erase(strings.begin());
    return retval;
}

template <class AssignTo, class ConvertTo>
inline typename std::enable_if<!is_mutable_container<ConvertTo>::value && (type_count<ConvertTo>::value > 1) &&
                                   type_count<ConvertTo>::value == type_count_min<ConvertTo>::value,
                               bool>::type
tuple_type_conversion(std::vector<std::string> &strings, AssignTo &output) {
    auto retval = lexical_conversion<AssignTo, ConvertTo>(strings, output);
    strings.erase(strings.begin(), strings.begin() + type_count<ConvertTo>::value);
    return retval;
}

template <class AssignTo, class ConvertTo>
inline typename std::enable_if<is_mutable_container<ConvertTo>::value ||
                                   type_count<ConvertTo>::value != type_count_min<ConvertTo>::value,
                               bool>::type
tuple_type_conversion(std::vector<std::string> &strings, AssignTo &output) {

    std::size_t index{subtype_count_min<ConvertTo>::value};
    const std::size_t mx_count{subtype_count<ConvertTo>::value};
    const std::size_t mx{(std::max)(mx_count, strings.size())};

    while(index < mx) {
        if(is_separator(strings[index])) {
            break;
        }
        ++index;
    }
    bool retval = lexical_conversion<AssignTo, ConvertTo>(
        std::vector<std::string>(strings.begin(), strings.begin() + static_cast<std::ptrdiff_t>(index)), output);
    strings.erase(strings.begin(), strings.begin() + static_cast<std::ptrdiff_t>(index) + 1);
    return retval;
}

template <class AssignTo, class ConvertTo, std::size_t I>
inline typename std::enable_if<(I < type_count_base<AssignTo>::value), bool>::type
tuple_conversion(std::vector<std::string> strings, AssignTo &output) {
    bool retval = true;
    using ConvertToElement = typename std::
        conditional<is_tuple_like<ConvertTo>::value, typename std::tuple_element<I, ConvertTo>::type, ConvertTo>::type;
    if(!strings.empty()) {
        retval = retval && tuple_type_conversion<typename std::tuple_element<I, AssignTo>::type, ConvertToElement>(
                               strings, std::get<I>(output));
    }
    retval = retval && tuple_conversion<AssignTo, ConvertTo, I + 1>(std::move(strings), output);
    return retval;
}

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_mutable_container<AssignTo>::value && is_mutable_container<ConvertTo>::value &&
                          type_count_base<ConvertTo>::value == 2,
                      detail::enabler>>
bool lexical_conversion(std::vector<std::string> strings, AssignTo &output) {
    output.clear();
    while(!strings.empty()) {

        typename std::remove_const<typename std::tuple_element<0, typename ConvertTo::value_type>::type>::type v1;
        typename std::tuple_element<1, typename ConvertTo::value_type>::type v2;
        bool retval = tuple_type_conversion<decltype(v1), decltype(v1)>(strings, v1);
        if(!strings.empty()) {
            retval = retval && tuple_type_conversion<decltype(v2), decltype(v2)>(strings, v2);
        }
        if(retval) {
            output.insert(output.end(), typename AssignTo::value_type{v1, v2});
        } else {
            return false;
        }
    }
    return (!output.empty());
}

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_tuple_like<AssignTo>::value && is_tuple_like<ConvertTo>::value &&
                          (type_count_base<ConvertTo>::value != type_count<ConvertTo>::value ||
                           type_count<ConvertTo>::value > 2),
                      detail::enabler>>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {
    static_assert(
        !is_tuple_like<ConvertTo>::value || type_count_base<AssignTo>::value == type_count_base<ConvertTo>::value,
        "if the conversion type is defined as a tuple it must be the same size as the type you are converting to");
    return tuple_conversion<AssignTo, ConvertTo, 0>(strings, output);
}

template <class AssignTo,
          class ConvertTo,
          enable_if_t<is_mutable_container<AssignTo>::value && is_mutable_container<ConvertTo>::value &&
                          type_count_base<ConvertTo>::value != 2 &&
                          ((type_count<ConvertTo>::value > 2) ||
                           (type_count<ConvertTo>::value > type_count_base<ConvertTo>::value)),
                      detail::enabler>>
bool lexical_conversion(const std::vector<std ::string> &strings, AssignTo &output) {
    bool retval = true;
    output.clear();
    std::vector<std::string> temp;
    std::size_t ii{0};
    std::size_t icount{0};
    std::size_t xcm{type_count<ConvertTo>::value};
    auto ii_max = strings.size();
    while(ii < ii_max) {
        temp.push_back(strings[ii]);
        ++ii;
        ++icount;
        if(icount == xcm || is_separator(temp.back()) || ii == ii_max) {
            if(static_cast<int>(xcm) > type_count_min<ConvertTo>::value && is_separator(temp.back())) {
                temp.pop_back();
            }
            typename AssignTo::value_type temp_out;
            retval = retval &&
                     lexical_conversion<typename AssignTo::value_type, typename ConvertTo::value_type>(temp, temp_out);
            temp.clear();
            if(!retval) {
                return false;
            }
            output.insert(output.end(), std::move(temp_out));
            icount = 0;
        }
    }
    return retval;
}

template <typename AssignTo,
          class ConvertTo,
          enable_if_t<classify_object<ConvertTo>::value == object_category::wrapper_value &&
                          std::is_assignable<ConvertTo &, ConvertTo>::value,
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std::string> &strings, AssignTo &output) {
    if(strings.empty() || strings.front().empty()) {
        output = ConvertTo{};
        return true;
    }
    typename ConvertTo::value_type val;
    if(lexical_conversion<typename ConvertTo::value_type, typename ConvertTo::value_type>(strings, val)) {
        output = ConvertTo{val};
        return true;
    }
    return false;
}

template <typename AssignTo,
          class ConvertTo,
          enable_if_t<classify_object<ConvertTo>::value == object_category::wrapper_value &&
                          !std::is_assignable<AssignTo &, ConvertTo>::value,
                      detail::enabler> = detail::dummy>
bool lexical_conversion(const std::vector<std::string> &strings, AssignTo &output) {
    using ConvertType = typename ConvertTo::value_type;
    if(strings.empty() || strings.front().empty()) {
        output = ConvertType{};
        return true;
    }
    ConvertType val;
    if(lexical_conversion<typename ConvertTo::value_type, typename ConvertTo::value_type>(strings, val)) {
        output = val;
        return true;
    }
    return false;
}

inline std::string sum_string_vector(const std::vector<std::string> &values) {
    double val{0.0};
    bool fail{false};
    std::string output;
    for(const auto &arg : values) {
        double tv{0.0};
        auto comp = detail::lexical_cast<double>(arg, tv);
        if(!comp) {
            try {
                tv = static_cast<double>(detail::to_flag_value(arg));
            } catch(const std::exception &) {
                fail = true;
                break;
            }
        }
        val += tv;
    }
    if(fail) {
        for(const auto &arg : values) {
            output.append(arg);
        }
    } else {
        if(val <= static_cast<double>((std::numeric_limits<std::int64_t>::min)()) ||
           val >= static_cast<double>((std::numeric_limits<std::int64_t>::max)()) ||
           // NOLINTNEXTLINE(clang-diagnostic-float-equal,bugprone-narrowing-conversions)
           val == static_cast<std::int64_t>(val)) {
            output = detail::value_string(static_cast<int64_t>(val));
        } else {
            output = detail::value_string(val);
        }
    }
    return output;
}

}  // namespace detail



namespace detail {

// Returns false if not a short option. Otherwise, sets opt name and rest and returns true
CLI11_INLINE bool split_short(const std::string &current, std::string &name, std::string &rest);

// Returns false if not a long option. Otherwise, sets opt name and other side of = and returns true
CLI11_INLINE bool split_long(const std::string &current, std::string &name, std::string &value);

// Returns false if not a windows style option. Otherwise, sets opt name and value and returns true
CLI11_INLINE bool split_windows_style(const std::string &current, std::string &name, std::string &value);

// Splits a string into multiple long and short names
CLI11_INLINE std::vector<std::string> split_names(std::string current);

CLI11_INLINE std::vector<std::pair<std::string, std::string>> get_default_flag_values(const std::string &str);

CLI11_INLINE std::tuple<std::vector<std::string>, std::vector<std::string>, std::string>
get_names(const std::vector<std::string> &input);

}  // namespace detail



namespace detail {

CLI11_INLINE bool split_short(const std::string &current, std::string &name, std::string &rest) {
    if(current.size() > 1 && current[0] == '-' && valid_first_char(current[1])) {
        name = current.substr(1, 1);
        rest = current.substr(2);
        return true;
    }
    return false;
}

CLI11_INLINE bool split_long(const std::string &current, std::string &name, std::string &value) {
    if(current.size() > 2 && current.substr(0, 2) == "--" && valid_first_char(current[2])) {
        auto loc = current.find_first_of('=');
        if(loc != std::string::npos) {
            name = current.substr(2, loc - 2);
            value = current.substr(loc + 1);
        } else {
            name = current.substr(2);
            value = "";
        }
        return true;
    }
    return false;
}

CLI11_INLINE bool split_windows_style(const std::string &current, std::string &name, std::string &value) {
    if(current.size() > 1 && current[0] == '/' && valid_first_char(current[1])) {
        auto loc = current.find_first_of(':');
        if(loc != std::string::npos) {
            name = current.substr(1, loc - 1);
            value = current.substr(loc + 1);
        } else {
            name = current.substr(1);
            value = "";
        }
        return true;
    }
    return false;
}

CLI11_INLINE std::vector<std::string> split_names(std::string current) {
    std::vector<std::string> output;
    std::size_t val = 0;
    while((val = current.find(',')) != std::string::npos) {
        output.push_back(trim_copy(current.substr(0, val)));
        current = current.substr(val + 1);
    }
    output.push_back(trim_copy(current));
    return output;
}

CLI11_INLINE std::vector<std::pair<std::string, std::string>> get_default_flag_values(const std::string &str) {
    std::vector<std::string> flags = split_names(str);
    flags.erase(std::remove_if(flags.begin(),
                               flags.end(),
                               [](const std::string &name) {
                                   return ((name.empty()) || (!(((name.find_first_of('{') != std::string::npos) &&
                                                                 (name.back() == '}')) ||
                                                                (name[0] == '!'))));
                               }),
                flags.end());
    std::vector<std::pair<std::string, std::string>> output;
    output.reserve(flags.size());
    for(auto &flag : flags) {
        auto def_start = flag.find_first_of('{');
        std::string defval = "false";
        if((def_start != std::string::npos) && (flag.back() == '}')) {
            defval = flag.substr(def_start + 1);
            defval.pop_back();
            flag.erase(def_start, std::string::npos);  // NOLINT(readability-suspicious-call-argument)
        }
        flag.erase(0, flag.find_first_not_of("-!"));
        output.emplace_back(flag, defval);
    }
    return output;
}

CLI11_INLINE std::tuple<std::vector<std::string>, std::vector<std::string>, std::string>
get_names(const std::vector<std::string> &input) {

    std::vector<std::string> short_names;
    std::vector<std::string> long_names;
    std::string pos_name;

    for(std::string name : input) {
        if(name.length() == 0) {
            continue;
        }
        if(name.length() > 1 && name[0] == '-' && name[1] != '-') {
            if(name.length() == 2 && valid_first_char(name[1]))
                short_names.emplace_back(1, name[1]);
            else
                throw BadNameString::OneCharName(name);
        } else if(name.length() > 2 && name.substr(0, 2) == "--") {
            name = name.substr(2);
            if(valid_name_string(name))
                long_names.push_back(name);
            else
                throw BadNameString::BadLongName(name);
        } else if(name == "-" || name == "--") {
            throw BadNameString::DashesOnly(name);
        } else {
            if(pos_name.length() > 0)
                throw BadNameString::MultiPositionalNames(name);
            pos_name = name;
        }
    }

    return std::make_tuple(short_names, long_names, pos_name);
}

}  // namespace detail



class App;

struct ConfigItem {
    std::vector<std::string> parents{};

    std::string name{};

    std::vector<std::string> inputs{};

    CLI11_NODISCARD std::string fullname() const {
        std::vector<std::string> tmp = parents;
        tmp.emplace_back(name);
        return detail::join(tmp, ".");
    }
};

class Config {
  protected:
    std::vector<ConfigItem> items{};

  public:
    virtual std::string to_config(const App *, bool, bool, std::string) const = 0;

    virtual std::vector<ConfigItem> from_config(std::istream &) const = 0;

    CLI11_NODISCARD virtual std::string to_flag(const ConfigItem &item) const {
        if(item.inputs.size() == 1) {
            return item.inputs.at(0);
        }
        if(item.inputs.empty()) {
            return "{}";
        }
        throw ConversionError::TooManyInputsFlag(item.fullname());  // LCOV_EXCL_LINE
    }

    CLI11_NODISCARD std::vector<ConfigItem> from_file(const std::string &name) const {
        std::ifstream input{name};
        if(!input.good())
            throw FileError::Missing(name);

        return from_config(input);
    }

    virtual ~Config() = default;
};

class ConfigBase : public Config {
  protected:
    char commentChar = '#';
    char arrayStart = '[';
    char arrayEnd = ']';
    char arraySeparator = ',';
    char valueDelimiter = '=';
    char stringQuote = '"';
    char characterQuote = '\'';
    uint8_t maximumLayers{255};
    char parentSeparatorChar{'.'};
    int16_t configIndex{-1};
    std::string configSection{};

  public:
    std::string
    to_config(const App * /*app*/, bool default_also, bool write_description, std::string prefix) const override;

    std::vector<ConfigItem> from_config(std::istream &input) const override;
    ConfigBase *comment(char cchar) {
        commentChar = cchar;
        return this;
    }
    ConfigBase *arrayBounds(char aStart, char aEnd) {
        arrayStart = aStart;
        arrayEnd = aEnd;
        return this;
    }
    ConfigBase *arrayDelimiter(char aSep) {
        arraySeparator = aSep;
        return this;
    }
    ConfigBase *valueSeparator(char vSep) {
        valueDelimiter = vSep;
        return this;
    }
    ConfigBase *quoteCharacter(char qString, char qChar) {
        stringQuote = qString;
        characterQuote = qChar;
        return this;
    }
    ConfigBase *maxLayers(uint8_t layers) {
        maximumLayers = layers;
        return this;
    }
    ConfigBase *parentSeparator(char sep) {
        parentSeparatorChar = sep;
        return this;
    }
    std::string &sectionRef() { return configSection; }
    CLI11_NODISCARD const std::string &section() const { return configSection; }
    ConfigBase *section(const std::string &sectionName) {
        configSection = sectionName;
        return this;
    }

    int16_t &indexRef() { return configIndex; }
    CLI11_NODISCARD int16_t index() const { return configIndex; }
    ConfigBase *index(int16_t sectionIndex) {
        configIndex = sectionIndex;
        return this;
    }
};

using ConfigTOML = ConfigBase;

class ConfigINI : public ConfigTOML {

  public:
    ConfigINI() {
        commentChar = ';';
        arrayStart = '\0';
        arrayEnd = '\0';
        arraySeparator = ' ';
        valueDelimiter = '=';
    }
};



class Option;



class Validator {
  protected:
    std::function<std::string()> desc_function_{[]() { return std::string{}; }};

    std::function<std::string(std::string &)> func_{[](std::string &) { return std::string{}; }};
    std::string name_{};
    int application_index_ = -1;
    bool active_{true};
    bool non_modifying_{false};

    Validator(std::string validator_desc, std::function<std::string(std::string &)> func)
        : desc_function_([validator_desc]() { return validator_desc; }), func_(std::move(func)) {}

  public:
    Validator() = default;
    explicit Validator(std::string validator_desc) : desc_function_([validator_desc]() { return validator_desc; }) {}
    Validator(std::function<std::string(std::string &)> op, std::string validator_desc, std::string validator_name = "")
        : desc_function_([validator_desc]() { return validator_desc; }), func_(std::move(op)),
          name_(std::move(validator_name)) {}
    Validator &operation(std::function<std::string(std::string &)> op) {
        func_ = std::move(op);
        return *this;
    }
    std::string operator()(std::string &str) const;

    std::string operator()(const std::string &str) const {
        std::string value = str;
        return (active_) ? func_(value) : std::string{};
    }

    Validator &description(std::string validator_desc) {
        desc_function_ = [validator_desc]() { return validator_desc; };
        return *this;
    }
    CLI11_NODISCARD Validator description(std::string validator_desc) const;

    CLI11_NODISCARD std::string get_description() const {
        if(active_) {
            return desc_function_();
        }
        return std::string{};
    }
    Validator &name(std::string validator_name) {
        name_ = std::move(validator_name);
        return *this;
    }
    CLI11_NODISCARD Validator name(std::string validator_name) const {
        Validator newval(*this);
        newval.name_ = std::move(validator_name);
        return newval;
    }
    CLI11_NODISCARD const std::string &get_name() const { return name_; }
    Validator &active(bool active_val = true) {
        active_ = active_val;
        return *this;
    }
    CLI11_NODISCARD Validator active(bool active_val = true) const {
        Validator newval(*this);
        newval.active_ = active_val;
        return newval;
    }

    Validator &non_modifying(bool no_modify = true) {
        non_modifying_ = no_modify;
        return *this;
    }
    Validator &application_index(int app_index) {
        application_index_ = app_index;
        return *this;
    }
    CLI11_NODISCARD Validator application_index(int app_index) const {
        Validator newval(*this);
        newval.application_index_ = app_index;
        return newval;
    }
    CLI11_NODISCARD int get_application_index() const { return application_index_; }
    CLI11_NODISCARD bool get_active() const { return active_; }

    CLI11_NODISCARD bool get_modifying() const { return !non_modifying_; }

    Validator operator&(const Validator &other) const;

    Validator operator|(const Validator &other) const;

    Validator operator!() const;

  private:
    void _merge_description(const Validator &val1, const Validator &val2, const std::string &merger);
};

class CustomValidator : public Validator {
  public:
};
// The implementation of the built in validators is using the Validator class;
// the user is only expected to use the const (static) versions (since there's no setup).
// Therefore, this is in detail.
namespace detail {

enum class path_type { nonexistent, file, directory };

CLI11_INLINE path_type check_path(const char *file) noexcept;

class ExistingFileValidator : public Validator {
  public:
    ExistingFileValidator();
};

class ExistingDirectoryValidator : public Validator {
  public:
    ExistingDirectoryValidator();
};

class ExistingPathValidator : public Validator {
  public:
    ExistingPathValidator();
};

class NonexistentPathValidator : public Validator {
  public:
    NonexistentPathValidator();
};

class IPV4Validator : public Validator {
  public:
    IPV4Validator();
};

}  // namespace detail

// Static is not needed here, because global const implies static.

const detail::ExistingFileValidator ExistingFile;

const detail::ExistingDirectoryValidator ExistingDirectory;

const detail::ExistingPathValidator ExistingPath;

const detail::NonexistentPathValidator NonexistentPath;

const detail::IPV4Validator ValidIPV4;

template <typename DesiredType> class TypeValidator : public Validator {
  public:
    explicit TypeValidator(const std::string &validator_name)
        : Validator(validator_name, [](std::string &input_string) {
              auto val = DesiredType();
              if(!detail::lexical_cast(input_string, val)) {
                  return std::string("Failed parsing ") + input_string + " as a " + detail::type_name<DesiredType>();
              }
              return std::string();
          }) {}
    TypeValidator() : TypeValidator(detail::type_name<DesiredType>()) {}
};

const TypeValidator<double> Number("NUMBER");

class FileOnDefaultPath : public Validator {
  public:
    explicit FileOnDefaultPath(std::string default_path, bool enableErrorReturn = true);
};

class Range : public Validator {
  public:
    template <typename T>
    Range(T min_val, T max_val, const std::string &validator_name = std::string{}) : Validator(validator_name) {
        if(validator_name.empty()) {
            std::stringstream out;
            out << detail::type_name<T>() << " in [" << min_val << " - " << max_val << "]";
            description(out.str());
        }

        func_ = [min_val, max_val](std::string &input) {
            T val;
            bool converted = detail::lexical_cast(input, val);
            if((!converted) || (val < min_val || val > max_val)) {
                std::stringstream out;
                out << "Value " << input << " not in range [";
                out << min_val << " - " << max_val << "]";
                return out.str();
            }
            return std::string{};
        };
    }

    template <typename T>
    explicit Range(T max_val, const std::string &validator_name = std::string{})
        : Range(static_cast<T>(0), max_val, validator_name) {}
};

const Range NonNegativeNumber((std::numeric_limits<double>::max)(), "NONNEGATIVE");

const Range PositiveNumber((std::numeric_limits<double>::min)(), (std::numeric_limits<double>::max)(), "POSITIVE");

class Bound : public Validator {
  public:
    template <typename T> Bound(T min_val, T max_val) {
        std::stringstream out;
        out << detail::type_name<T>() << " bounded to [" << min_val << " - " << max_val << "]";
        description(out.str());

        func_ = [min_val, max_val](std::string &input) {
            T val;
            bool converted = detail::lexical_cast(input, val);
            if(!converted) {
                return std::string("Value ") + input + " could not be converted";
            }
            if(val < min_val)
                input = detail::to_string(min_val);
            else if(val > max_val)
                input = detail::to_string(max_val);

            return std::string{};
        };
    }

    template <typename T> explicit Bound(T max_val) : Bound(static_cast<T>(0), max_val) {}
};

namespace detail {
template <typename T,
          enable_if_t<is_copyable_ptr<typename std::remove_reference<T>::type>::value, detail::enabler> = detail::dummy>
auto smart_deref(T value) -> decltype(*value) {
    return *value;
}

template <
    typename T,
    enable_if_t<!is_copyable_ptr<typename std::remove_reference<T>::type>::value, detail::enabler> = detail::dummy>
typename std::remove_reference<T>::type &smart_deref(T &value) {
    return value;
}
template <typename T> std::string generate_set(const T &set) {
    using element_t = typename detail::element_type<T>::type;
    using iteration_type_t = typename detail::pair_adaptor<element_t>::value_type;  // the type of the object pair
    std::string out(1, '{');
    out.append(detail::join(
        detail::smart_deref(set),
        [](const iteration_type_t &v) { return detail::pair_adaptor<element_t>::first(v); },
        ","));
    out.push_back('}');
    return out;
}

template <typename T> std::string generate_map(const T &map, bool key_only = false) {
    using element_t = typename detail::element_type<T>::type;
    using iteration_type_t = typename detail::pair_adaptor<element_t>::value_type;  // the type of the object pair
    std::string out(1, '{');
    out.append(detail::join(
        detail::smart_deref(map),
        [key_only](const iteration_type_t &v) {
            std::string res{detail::to_string(detail::pair_adaptor<element_t>::first(v))};

            if(!key_only) {
                res.append("->");
                res += detail::to_string(detail::pair_adaptor<element_t>::second(v));
            }
            return res;
        },
        ","));
    out.push_back('}');
    return out;
}

template <typename C, typename V> struct has_find {
    template <typename CC, typename VV>
    static auto test(int) -> decltype(std::declval<CC>().find(std::declval<VV>()), std::true_type());
    template <typename, typename> static auto test(...) -> decltype(std::false_type());

    static const auto value = decltype(test<C, V>(0))::value;
    using type = std::integral_constant<bool, value>;
};

template <typename T, typename V, enable_if_t<!has_find<T, V>::value, detail::enabler> = detail::dummy>
auto search(const T &set, const V &val) -> std::pair<bool, decltype(std::begin(detail::smart_deref(set)))> {
    using element_t = typename detail::element_type<T>::type;
    auto &setref = detail::smart_deref(set);
    auto it = std::find_if(std::begin(setref), std::end(setref), [&val](decltype(*std::begin(setref)) v) {
        return (detail::pair_adaptor<element_t>::first(v) == val);
    });
    return {(it != std::end(setref)), it};
}

template <typename T, typename V, enable_if_t<has_find<T, V>::value, detail::enabler> = detail::dummy>
auto search(const T &set, const V &val) -> std::pair<bool, decltype(std::begin(detail::smart_deref(set)))> {
    auto &setref = detail::smart_deref(set);
    auto it = setref.find(val);
    return {(it != std::end(setref)), it};
}

template <typename T, typename V>
auto search(const T &set, const V &val, const std::function<V(V)> &filter_function)
    -> std::pair<bool, decltype(std::begin(detail::smart_deref(set)))> {
    using element_t = typename detail::element_type<T>::type;
    // do the potentially faster first search
    auto res = search(set, val);
    if((res.first) || (!(filter_function))) {
        return res;
    }
    // if we haven't found it do the longer linear search with all the element translations
    auto &setref = detail::smart_deref(set);
    auto it = std::find_if(std::begin(setref), std::end(setref), [&](decltype(*std::begin(setref)) v) {
        V a{detail::pair_adaptor<element_t>::first(v)};
        a = filter_function(a);
        return (a == val);
    });
    return {(it != std::end(setref)), it};
}

// the following suggestion was made by Nikita Ofitserov(@himikof)
// done in templates to prevent compiler warnings on negation of unsigned numbers

template <typename T>
inline typename std::enable_if<std::is_signed<T>::value, T>::type overflowCheck(const T &a, const T &b) {
    if((a > 0) == (b > 0)) {
        return ((std::numeric_limits<T>::max)() / (std::abs)(a) < (std::abs)(b));
    }
    return ((std::numeric_limits<T>::min)() / (std::abs)(a) > -(std::abs)(b));
}
template <typename T>
inline typename std::enable_if<!std::is_signed<T>::value, T>::type overflowCheck(const T &a, const T &b) {
    return ((std::numeric_limits<T>::max)() / a < b);
}

template <typename T> typename std::enable_if<std::is_integral<T>::value, bool>::type checked_multiply(T &a, T b) {
    if(a == 0 || b == 0 || a == 1 || b == 1) {
        a *= b;
        return true;
    }
    if(a == (std::numeric_limits<T>::min)() || b == (std::numeric_limits<T>::min)()) {
        return false;
    }
    if(overflowCheck(a, b)) {
        return false;
    }
    a *= b;
    return true;
}

template <typename T>
typename std::enable_if<std::is_floating_point<T>::value, bool>::type checked_multiply(T &a, T b) {
    T c = a * b;
    if(std::isinf(c) && !std::isinf(a) && !std::isinf(b)) {
        return false;
    }
    a = c;
    return true;
}

}  // namespace detail
class IsMember : public Validator {
  public:
    using filter_fn_t = std::function<std::string(std::string)>;

    template <typename T, typename... Args>
    IsMember(std::initializer_list<T> values, Args &&...args)
        : IsMember(std::vector<T>(values), std::forward<Args>(args)...) {}

    template <typename T> explicit IsMember(T &&set) : IsMember(std::forward<T>(set), nullptr) {}

    template <typename T, typename F> explicit IsMember(T set, F filter_function) {

        // Get the type of the contained item - requires a container have ::value_type
        // if the type does not have first_type and second_type, these are both value_type
        using element_t = typename detail::element_type<T>::type;             // Removes (smart) pointers if needed
        using item_t = typename detail::pair_adaptor<element_t>::first_type;  // Is value_type if not a map

        using local_item_t = typename IsMemberType<item_t>::type;  // This will convert bad types to good ones
                                                                   // (const char * to std::string)

        // Make a local copy of the filter function, using a std::function if not one already
        std::function<local_item_t(local_item_t)> filter_fn = filter_function;

        // This is the type name for help, it will take the current version of the set contents
        desc_function_ = [set]() { return detail::generate_set(detail::smart_deref(set)); };

        // This is the function that validates
        // It stores a copy of the set pointer-like, so shared_ptr will stay alive
        func_ = [set, filter_fn](std::string &input) {
            local_item_t b;
            if(!detail::lexical_cast(input, b)) {
                throw ValidationError(input);  // name is added later
            }
            if(filter_fn) {
                b = filter_fn(b);
            }
            auto res = detail::search(set, b, filter_fn);
            if(res.first) {
                // Make sure the version in the input string is identical to the one in the set
                if(filter_fn) {
                    input = detail::value_string(detail::pair_adaptor<element_t>::first(*(res.second)));
                }

                // Return empty error string (success)
                return std::string{};
            }

            // If you reach this point, the result was not found
            return input + " not in " + detail::generate_set(detail::smart_deref(set));
        };
    }

    template <typename T, typename... Args>
    IsMember(T &&set, filter_fn_t filter_fn_1, filter_fn_t filter_fn_2, Args &&...other)
        : IsMember(
              std::forward<T>(set),
              [filter_fn_1, filter_fn_2](std::string a) { return filter_fn_2(filter_fn_1(a)); },
              other...) {}
};

template <typename T> using TransformPairs = std::vector<std::pair<std::string, T>>;

class Transformer : public Validator {
  public:
    using filter_fn_t = std::function<std::string(std::string)>;

    template <typename... Args>
    Transformer(std::initializer_list<std::pair<std::string, std::string>> values, Args &&...args)
        : Transformer(TransformPairs<std::string>(values), std::forward<Args>(args)...) {}

    template <typename T> explicit Transformer(T &&mapping) : Transformer(std::forward<T>(mapping), nullptr) {}

    template <typename T, typename F> explicit Transformer(T mapping, F filter_function) {

        static_assert(detail::pair_adaptor<typename detail::element_type<T>::type>::value,
                      "mapping must produce value pairs");
        // Get the type of the contained item - requires a container have ::value_type
        // if the type does not have first_type and second_type, these are both value_type
        using element_t = typename detail::element_type<T>::type;             // Removes (smart) pointers if needed
        using item_t = typename detail::pair_adaptor<element_t>::first_type;  // Is value_type if not a map
        using local_item_t = typename IsMemberType<item_t>::type;             // Will convert bad types to good ones
                                                                              // (const char * to std::string)

        // Make a local copy of the filter function, using a std::function if not one already
        std::function<local_item_t(local_item_t)> filter_fn = filter_function;

        // This is the type name for help, it will take the current version of the set contents
        desc_function_ = [mapping]() { return detail::generate_map(detail::smart_deref(mapping)); };

        func_ = [mapping, filter_fn](std::string &input) {
            local_item_t b;
            if(!detail::lexical_cast(input, b)) {
                return std::string();
                // there is no possible way we can match anything in the mapping if we can't convert so just return
            }
            if(filter_fn) {
                b = filter_fn(b);
            }
            auto res = detail::search(mapping, b, filter_fn);
            if(res.first) {
                input = detail::value_string(detail::pair_adaptor<element_t>::second(*res.second));
            }
            return std::string{};
        };
    }

    template <typename T, typename... Args>
    Transformer(T &&mapping, filter_fn_t filter_fn_1, filter_fn_t filter_fn_2, Args &&...other)
        : Transformer(
              std::forward<T>(mapping),
              [filter_fn_1, filter_fn_2](std::string a) { return filter_fn_2(filter_fn_1(a)); },
              other...) {}
};

class CheckedTransformer : public Validator {
  public:
    using filter_fn_t = std::function<std::string(std::string)>;

    template <typename... Args>
    CheckedTransformer(std::initializer_list<std::pair<std::string, std::string>> values, Args &&...args)
        : CheckedTransformer(TransformPairs<std::string>(values), std::forward<Args>(args)...) {}

    template <typename T> explicit CheckedTransformer(T mapping) : CheckedTransformer(std::move(mapping), nullptr) {}

    template <typename T, typename F> explicit CheckedTransformer(T mapping, F filter_function) {

        static_assert(detail::pair_adaptor<typename detail::element_type<T>::type>::value,
                      "mapping must produce value pairs");
        // Get the type of the contained item - requires a container have ::value_type
        // if the type does not have first_type and second_type, these are both value_type
        using element_t = typename detail::element_type<T>::type;             // Removes (smart) pointers if needed
        using item_t = typename detail::pair_adaptor<element_t>::first_type;  // Is value_type if not a map
        using local_item_t = typename IsMemberType<item_t>::type;             // Will convert bad types to good ones
                                                                              // (const char * to std::string)
        using iteration_type_t = typename detail::pair_adaptor<element_t>::value_type;  // the type of the object pair

        // Make a local copy of the filter function, using a std::function if not one already
        std::function<local_item_t(local_item_t)> filter_fn = filter_function;

        auto tfunc = [mapping]() {
            std::string out("value in ");
            out += detail::generate_map(detail::smart_deref(mapping)) + " OR {";
            out += detail::join(
                detail::smart_deref(mapping),
                [](const iteration_type_t &v) { return detail::to_string(detail::pair_adaptor<element_t>::second(v)); },
                ",");
            out.push_back('}');
            return out;
        };

        desc_function_ = tfunc;

        func_ = [mapping, tfunc, filter_fn](std::string &input) {
            local_item_t b;
            bool converted = detail::lexical_cast(input, b);
            if(converted) {
                if(filter_fn) {
                    b = filter_fn(b);
                }
                auto res = detail::search(mapping, b, filter_fn);
                if(res.first) {
                    input = detail::value_string(detail::pair_adaptor<element_t>::second(*res.second));
                    return std::string{};
                }
            }
            for(const auto &v : detail::smart_deref(mapping)) {
                auto output_string = detail::value_string(detail::pair_adaptor<element_t>::second(v));
                if(output_string == input) {
                    return std::string();
                }
            }

            return "Check " + input + " " + tfunc() + " FAILED";
        };
    }

    template <typename T, typename... Args>
    CheckedTransformer(T &&mapping, filter_fn_t filter_fn_1, filter_fn_t filter_fn_2, Args &&...other)
        : CheckedTransformer(
              std::forward<T>(mapping),
              [filter_fn_1, filter_fn_2](std::string a) { return filter_fn_2(filter_fn_1(a)); },
              other...) {}
};

inline std::string ignore_case(std::string item) { return detail::to_lower(item); }

inline std::string ignore_underscore(std::string item) { return detail::remove_underscore(item); }

inline std::string ignore_space(std::string item) {
    item.erase(std::remove(std::begin(item), std::end(item), ' '), std::end(item));
    item.erase(std::remove(std::begin(item), std::end(item), '\t'), std::end(item));
    return item;
}

class AsNumberWithUnit : public Validator {
  public:
    enum Options {
        CASE_SENSITIVE = 0,
        CASE_INSENSITIVE = 1,
        UNIT_OPTIONAL = 0,
        UNIT_REQUIRED = 2,
        DEFAULT = CASE_INSENSITIVE | UNIT_OPTIONAL
    };

    template <typename Number>
    explicit AsNumberWithUnit(std::map<std::string, Number> mapping,
                              Options opts = DEFAULT,
                              const std::string &unit_name = "UNIT") {
        description(generate_description<Number>(unit_name, opts));
        validate_mapping(mapping, opts);

        // transform function
        func_ = [mapping, opts](std::string &input) -> std::string {
            Number num{};

            detail::rtrim(input);
            if(input.empty()) {
                throw ValidationError("Input is empty");
            }

            // Find split position between number and prefix
            auto unit_begin = input.end();
            while(unit_begin > input.begin() && std::isalpha(*(unit_begin - 1), std::locale())) {
                --unit_begin;
            }

            std::string unit{unit_begin, input.end()};
            input.resize(static_cast<std::size_t>(std::distance(input.begin(), unit_begin)));
            detail::trim(input);

            if(opts & UNIT_REQUIRED && unit.empty()) {
                throw ValidationError("Missing mandatory unit");
            }
            if(opts & CASE_INSENSITIVE) {
                unit = detail::to_lower(unit);
            }
            if(unit.empty()) {
                if(!detail::lexical_cast(input, num)) {
                    throw ValidationError(std::string("Value ") + input + " could not be converted to " +
                                          detail::type_name<Number>());
                }
                // No need to modify input if no unit passed
                return {};
            }

            // find corresponding factor
            auto it = mapping.find(unit);
            if(it == mapping.end()) {
                throw ValidationError(unit +
                                      " unit not recognized. "
                                      "Allowed values: " +
                                      detail::generate_map(mapping, true));
            }

            if(!input.empty()) {
                bool converted = detail::lexical_cast(input, num);
                if(!converted) {
                    throw ValidationError(std::string("Value ") + input + " could not be converted to " +
                                          detail::type_name<Number>());
                }
                // perform safe multiplication
                bool ok = detail::checked_multiply(num, it->second);
                if(!ok) {
                    throw ValidationError(detail::to_string(num) + " multiplied by " + unit +
                                          " factor would cause number overflow. Use smaller value.");
                }
            } else {
                num = static_cast<Number>(it->second);
            }

            input = detail::to_string(num);

            return {};
        };
    }

  private:
    template <typename Number> static void validate_mapping(std::map<std::string, Number> &mapping, Options opts) {
        for(auto &kv : mapping) {
            if(kv.first.empty()) {
                throw ValidationError("Unit must not be empty.");
            }
            if(!detail::isalpha(kv.first)) {
                throw ValidationError("Unit must contain only letters.");
            }
        }

        // make all units lowercase if CASE_INSENSITIVE
        if(opts & CASE_INSENSITIVE) {
            std::map<std::string, Number> lower_mapping;
            for(auto &kv : mapping) {
                auto s = detail::to_lower(kv.first);
                if(lower_mapping.count(s)) {
                    throw ValidationError(std::string("Several matching lowercase unit representations are found: ") +
                                          s);
                }
                lower_mapping[detail::to_lower(kv.first)] = kv.second;
            }
            mapping = std::move(lower_mapping);
        }
    }

    template <typename Number> static std::string generate_description(const std::string &name, Options opts) {
        std::stringstream out;
        out << detail::type_name<Number>() << ' ';
        if(opts & UNIT_REQUIRED) {
            out << name;
        } else {
            out << '[' << name << ']';
        }
        return out.str();
    }
};

inline AsNumberWithUnit::Options operator|(const AsNumberWithUnit::Options &a, const AsNumberWithUnit::Options &b) {
    return static_cast<AsNumberWithUnit::Options>(static_cast<int>(a) | static_cast<int>(b));
}

class AsSizeValue : public AsNumberWithUnit {
  public:
    using result_t = std::uint64_t;

    explicit AsSizeValue(bool kb_is_1000);

  private:
    static std::map<std::string, result_t> init_mapping(bool kb_is_1000);

    static std::map<std::string, result_t> get_mapping(bool kb_is_1000);
};

namespace detail {
CLI11_INLINE std::pair<std::string, std::string> split_program_name(std::string commandline);

}  // namespace detail




CLI11_INLINE std::string Validator::operator()(std::string &str) const {
    std::string retstring;
    if(active_) {
        if(non_modifying_) {
            std::string value = str;
            retstring = func_(value);
        } else {
            retstring = func_(str);
        }
    }
    return retstring;
}

CLI11_NODISCARD CLI11_INLINE Validator Validator::description(std::string validator_desc) const {
    Validator newval(*this);
    newval.desc_function_ = [validator_desc]() { return validator_desc; };
    return newval;
}

CLI11_INLINE Validator Validator::operator&(const Validator &other) const {
    Validator newval;

    newval._merge_description(*this, other, " AND ");

    // Give references (will make a copy in lambda function)
    const std::function<std::string(std::string & filename)> &f1 = func_;
    const std::function<std::string(std::string & filename)> &f2 = other.func_;

    newval.func_ = [f1, f2](std::string &input) {
        std::string s1 = f1(input);
        std::string s2 = f2(input);
        if(!s1.empty() && !s2.empty())
            return std::string("(") + s1 + ") AND (" + s2 + ")";
        return s1 + s2;
    };

    newval.active_ = active_ && other.active_;
    newval.application_index_ = application_index_;
    return newval;
}

CLI11_INLINE Validator Validator::operator|(const Validator &other) const {
    Validator newval;

    newval._merge_description(*this, other, " OR ");

    // Give references (will make a copy in lambda function)
    const std::function<std::string(std::string &)> &f1 = func_;
    const std::function<std::string(std::string &)> &f2 = other.func_;

    newval.func_ = [f1, f2](std::string &input) {
        std::string s1 = f1(input);
        std::string s2 = f2(input);
        if(s1.empty() || s2.empty())
            return std::string();

        return std::string("(") + s1 + ") OR (" + s2 + ")";
    };
    newval.active_ = active_ && other.active_;
    newval.application_index_ = application_index_;
    return newval;
}

CLI11_INLINE Validator Validator::operator!() const {
    Validator newval;
    const std::function<std::string()> &dfunc1 = desc_function_;
    newval.desc_function_ = [dfunc1]() {
        auto str = dfunc1();
        return (!str.empty()) ? std::string("NOT ") + str : std::string{};
    };
    // Give references (will make a copy in lambda function)
    const std::function<std::string(std::string & res)> &f1 = func_;

    newval.func_ = [f1, dfunc1](std::string &test) -> std::string {
        std::string s1 = f1(test);
        if(s1.empty()) {
            return std::string("check ") + dfunc1() + " succeeded improperly";
        }
        return std::string{};
    };
    newval.active_ = active_;
    newval.application_index_ = application_index_;
    return newval;
}

CLI11_INLINE void
Validator::_merge_description(const Validator &val1, const Validator &val2, const std::string &merger) {

    const std::function<std::string()> &dfunc1 = val1.desc_function_;
    const std::function<std::string()> &dfunc2 = val2.desc_function_;

    desc_function_ = [=]() {
        std::string f1 = dfunc1();
        std::string f2 = dfunc2();
        if((f1.empty()) || (f2.empty())) {
            return f1 + f2;
        }
        return std::string(1, '(') + f1 + ')' + merger + '(' + f2 + ')';
    };
}

namespace detail {

#if defined CLI11_HAS_FILESYSTEM && CLI11_HAS_FILESYSTEM > 0
CLI11_INLINE path_type check_path(const char *file) noexcept {
    std::error_code ec;
    auto stat = std::filesystem::status(file, ec);
    if(ec) {
        return path_type::nonexistent;
    }
    switch(stat.type()) {
    case std::filesystem::file_type::none:  // LCOV_EXCL_LINE
    case std::filesystem::file_type::not_found:
        return path_type::nonexistent;
    case std::filesystem::file_type::directory:
        return path_type::directory;
    case std::filesystem::file_type::symlink:
    case std::filesystem::file_type::block:
    case std::filesystem::file_type::character:
    case std::filesystem::file_type::fifo:
    case std::filesystem::file_type::socket:
    case std::filesystem::file_type::regular:
    case std::filesystem::file_type::unknown:
    default:
        return path_type::file;
    }
}
#else
CLI11_INLINE path_type check_path(const char *file) noexcept {
#if defined(_MSC_VER)
    struct __stat64 buffer;
    if(_stat64(file, &buffer) == 0) {
        return ((buffer.st_mode & S_IFDIR) != 0) ? path_type::directory : path_type::file;
    }
#else
    struct stat buffer;
    if(stat(file, &buffer) == 0) {
        return ((buffer.st_mode & S_IFDIR) != 0) ? path_type::directory : path_type::file;
    }
#endif
    return path_type::nonexistent;
}
#endif

CLI11_INLINE ExistingFileValidator::ExistingFileValidator() : Validator("FILE") {
    func_ = [](std::string &filename) {
        auto path_result = check_path(filename.c_str());
        if(path_result == path_type::nonexistent) {
            return "File does not exist: " + filename;
        }
        if(path_result == path_type::directory) {
            return "File is actually a directory: " + filename;
        }
        return std::string();
    };
}

CLI11_INLINE ExistingDirectoryValidator::ExistingDirectoryValidator() : Validator("DIR") {
    func_ = [](std::string &filename) {
        auto path_result = check_path(filename.c_str());
        if(path_result == path_type::nonexistent) {
            return "Directory does not exist: " + filename;
        }
        if(path_result == path_type::file) {
            return "Directory is actually a file: " + filename;
        }
        return std::string();
    };
}

CLI11_INLINE ExistingPathValidator::ExistingPathValidator() : Validator("PATH(existing)") {
    func_ = [](std::string &filename) {
        auto path_result = check_path(filename.c_str());
        if(path_result == path_type::nonexistent) {
            return "Path does not exist: " + filename;
        }
        return std::string();
    };
}

CLI11_INLINE NonexistentPathValidator::NonexistentPathValidator() : Validator("PATH(non-existing)") {
    func_ = [](std::string &filename) {
        auto path_result = check_path(filename.c_str());
        if(path_result != path_type::nonexistent) {
            return "Path already exists: " + filename;
        }
        return std::string();
    };
}

CLI11_INLINE IPV4Validator::IPV4Validator() : Validator("IPV4") {
    func_ = [](std::string &ip_addr) {
        auto result = CLI::detail::split(ip_addr, '.');
        if(result.size() != 4) {
            return std::string("Invalid IPV4 address must have four parts (") + ip_addr + ')';
        }
        int num = 0;
        for(const auto &var : result) {
            bool retval = detail::lexical_cast(var, num);
            if(!retval) {
                return std::string("Failed parsing number (") + var + ')';
            }
            if(num < 0 || num > 255) {
                return std::string("Each IP number must be between 0 and 255 ") + var;
            }
        }
        return std::string();
    };
}

}  // namespace detail

CLI11_INLINE FileOnDefaultPath::FileOnDefaultPath(std::string default_path, bool enableErrorReturn)
    : Validator("FILE") {
    func_ = [default_path, enableErrorReturn](std::string &filename) {
        auto path_result = detail::check_path(filename.c_str());
        if(path_result == detail::path_type::nonexistent) {
            std::string test_file_path = default_path;
            if(default_path.back() != '/' && default_path.back() != '\\') {
                // Add folder separator
                test_file_path += '/';
            }
            test_file_path.append(filename);
            path_result = detail::check_path(test_file_path.c_str());
            if(path_result == detail::path_type::file) {
                filename = test_file_path;
            } else {
                if(enableErrorReturn) {
                    return "File does not exist: " + filename;
                }
            }
        }
        return std::string{};
    };
}

CLI11_INLINE AsSizeValue::AsSizeValue(bool kb_is_1000) : AsNumberWithUnit(get_mapping(kb_is_1000)) {
    if(kb_is_1000) {
        description("SIZE [b, kb(=1000b), kib(=1024b), ...]");
    } else {
        description("SIZE [b, kb(=1024b), ...]");
    }
}

CLI11_INLINE std::map<std::string, AsSizeValue::result_t> AsSizeValue::init_mapping(bool kb_is_1000) {
    std::map<std::string, result_t> m;
    result_t k_factor = kb_is_1000 ? 1000 : 1024;
    result_t ki_factor = 1024;
    result_t k = 1;
    result_t ki = 1;
    m["b"] = 1;
    for(std::string p : {"k", "m", "g", "t", "p", "e"}) {
        k *= k_factor;
        ki *= ki_factor;
        m[p] = k;
        m[p + "b"] = k;
        m[p + "i"] = ki;
        m[p + "ib"] = ki;
    }
    return m;
}

CLI11_INLINE std::map<std::string, AsSizeValue::result_t> AsSizeValue::get_mapping(bool kb_is_1000) {
    if(kb_is_1000) {
        static auto m = init_mapping(true);
        return m;
    }
    static auto m = init_mapping(false);
    return m;
}

namespace detail {

CLI11_INLINE std::pair<std::string, std::string> split_program_name(std::string commandline) {
    // try to determine the programName
    std::pair<std::string, std::string> vals;
    trim(commandline);
    auto esp = commandline.find_first_of(' ', 1);
    while(detail::check_path(commandline.substr(0, esp).c_str()) != path_type::file) {
        esp = commandline.find_first_of(' ', esp + 1);
        if(esp == std::string::npos) {
            // if we have reached the end and haven't found a valid file just assume the first argument is the
            // program name
            if(commandline[0] == '"' || commandline[0] == '\'' || commandline[0] == '`') {
                bool embeddedQuote = false;
                auto keyChar = commandline[0];
                auto end = commandline.find_first_of(keyChar, 1);
                while((end != std::string::npos) && (commandline[end - 1] == '\\')) {  // deal with escaped quotes
                    end = commandline.find_first_of(keyChar, end + 1);
                    embeddedQuote = true;
                }
                if(end != std::string::npos) {
                    vals.first = commandline.substr(1, end - 1);
                    esp = end + 1;
                    if(embeddedQuote) {
                        vals.first = find_and_replace(vals.first, std::string("\\") + keyChar, std::string(1, keyChar));
                    }
                } else {
                    esp = commandline.find_first_of(' ', 1);
                }
            } else {
                esp = commandline.find_first_of(' ', 1);
            }

            break;
        }
    }
    if(vals.first.empty()) {
        vals.first = commandline.substr(0, esp);
        rtrim(vals.first);
    }

    // strip the program name
    vals.second = (esp < commandline.length() - 1) ? commandline.substr(esp + 1) : std::string{};
    ltrim(vals.second);
    return vals;
}

}  // namespace detail




class Option;
class App;


enum class AppFormatMode {
    Normal,  
    All,     
    Sub,     
};

class FormatterBase {
  protected:

    std::size_t column_width_{30};

    std::map<std::string, std::string> labels_{};


  public:
    FormatterBase() = default;
    FormatterBase(const FormatterBase &) = default;
    FormatterBase(FormatterBase &&) = default;
    FormatterBase &operator=(const FormatterBase &) = default;
    FormatterBase &operator=(FormatterBase &&) = default;

    virtual ~FormatterBase() noexcept {}  // NOLINT(modernize-use-equals-default)

    virtual std::string make_help(const App *, std::string, AppFormatMode) const = 0;


    void label(std::string key, std::string val) { labels_[key] = val; }

    void column_width(std::size_t val) { column_width_ = val; }


    CLI11_NODISCARD std::string get_label(std::string key) const {
        if(labels_.find(key) == labels_.end())
            return key;
        return labels_.at(key);
    }

    CLI11_NODISCARD std::size_t get_column_width() const { return column_width_; }

};

class FormatterLambda final : public FormatterBase {
    using funct_t = std::function<std::string(const App *, std::string, AppFormatMode)>;

    funct_t lambda_;

  public:
    explicit FormatterLambda(funct_t funct) : lambda_(std::move(funct)) {}

    ~FormatterLambda() noexcept override {}  // NOLINT(modernize-use-equals-default)

    std::string make_help(const App *app, std::string name, AppFormatMode mode) const override {
        return lambda_(app, name, mode);
    }
};

class Formatter : public FormatterBase {
  public:
    Formatter() = default;
    Formatter(const Formatter &) = default;
    Formatter(Formatter &&) = default;
    Formatter &operator=(const Formatter &) = default;
    Formatter &operator=(Formatter &&) = default;


    CLI11_NODISCARD virtual std::string
    make_group(std::string group, bool is_positional, std::vector<const Option *> opts) const;

    virtual std::string make_positionals(const App *app) const;

    std::string make_groups(const App *app, AppFormatMode mode) const;

    virtual std::string make_subcommands(const App *app, AppFormatMode mode) const;

    virtual std::string make_subcommand(const App *sub) const;

    virtual std::string make_expanded(const App *sub) const;

    virtual std::string make_footer(const App *app) const;

    virtual std::string make_description(const App *app) const;

    virtual std::string make_usage(const App *app, std::string name) const;

    std::string make_help(const App * /*app*/, std::string, AppFormatMode) const override;


    virtual std::string make_option(const Option *opt, bool is_positional) const {
        std::stringstream out;
        detail::format_help(
            out, make_option_name(opt, is_positional) + make_option_opts(opt), make_option_desc(opt), column_width_);
        return out.str();
    }

    virtual std::string make_option_name(const Option *, bool) const;

    virtual std::string make_option_opts(const Option *) const;

    virtual std::string make_option_desc(const Option *) const;

    virtual std::string make_option_usage(const Option *opt) const;

};




using results_t = std::vector<std::string>;
using callback_t = std::function<bool(const results_t &)>;

class Option;
class App;

using Option_p = std::unique_ptr<Option>;
enum class MultiOptionPolicy : char {
    Throw,      
    TakeLast,   
    TakeFirst,  
    Join,       
    TakeAll,    
    Sum         
};

template <typename CRTP> class OptionBase {
    friend App;

  protected:
    std::string group_ = std::string("Options");

    bool required_{false};

    bool ignore_case_{false};

    bool ignore_underscore_{false};

    bool configurable_{true};

    bool disable_flag_override_{false};

    char delimiter_{'\0'};

    bool always_capture_default_{false};

    MultiOptionPolicy multi_option_policy_{MultiOptionPolicy::Throw};

    template <typename T> void copy_to(T *other) const;

  public:
    // setters

    CRTP *group(const std::string &name) {
        if(!detail::valid_alias_name_string(name)) {
            throw IncorrectConstruction("Group names may not contain newlines or null characters");
        }
        group_ = name;
        return static_cast<CRTP *>(this);
    }

    CRTP *required(bool value = true) {
        required_ = value;
        return static_cast<CRTP *>(this);
    }

    CRTP *mandatory(bool value = true) { return required(value); }

    CRTP *always_capture_default(bool value = true) {
        always_capture_default_ = value;
        return static_cast<CRTP *>(this);
    }

    // Getters

    CLI11_NODISCARD const std::string &get_group() const { return group_; }

    CLI11_NODISCARD bool get_required() const { return required_; }

    CLI11_NODISCARD bool get_ignore_case() const { return ignore_case_; }

    CLI11_NODISCARD bool get_ignore_underscore() const { return ignore_underscore_; }

    CLI11_NODISCARD bool get_configurable() const { return configurable_; }

    CLI11_NODISCARD bool get_disable_flag_override() const { return disable_flag_override_; }

    CLI11_NODISCARD char get_delimiter() const { return delimiter_; }

    CLI11_NODISCARD bool get_always_capture_default() const { return always_capture_default_; }

    CLI11_NODISCARD MultiOptionPolicy get_multi_option_policy() const { return multi_option_policy_; }

    // Shortcuts for multi option policy

    CRTP *take_last() {
        auto *self = static_cast<CRTP *>(this);
        self->multi_option_policy(MultiOptionPolicy::TakeLast);
        return self;
    }

    CRTP *take_first() {
        auto *self = static_cast<CRTP *>(this);
        self->multi_option_policy(MultiOptionPolicy::TakeFirst);
        return self;
    }

    CRTP *take_all() {
        auto self = static_cast<CRTP *>(this);
        self->multi_option_policy(MultiOptionPolicy::TakeAll);
        return self;
    }

    CRTP *join() {
        auto *self = static_cast<CRTP *>(this);
        self->multi_option_policy(MultiOptionPolicy::Join);
        return self;
    }

    CRTP *join(char delim) {
        auto self = static_cast<CRTP *>(this);
        self->delimiter_ = delim;
        self->multi_option_policy(MultiOptionPolicy::Join);
        return self;
    }

    CRTP *configurable(bool value = true) {
        configurable_ = value;
        return static_cast<CRTP *>(this);
    }

    CRTP *delimiter(char value = '\0') {
        delimiter_ = value;
        return static_cast<CRTP *>(this);
    }
};

class OptionDefaults : public OptionBase<OptionDefaults> {
  public:
    OptionDefaults() = default;

    // Methods here need a different implementation if they are Option vs. OptionDefault

    OptionDefaults *multi_option_policy(MultiOptionPolicy value = MultiOptionPolicy::Throw) {
        multi_option_policy_ = value;
        return this;
    }

    OptionDefaults *ignore_case(bool value = true) {
        ignore_case_ = value;
        return this;
    }

    OptionDefaults *ignore_underscore(bool value = true) {
        ignore_underscore_ = value;
        return this;
    }

    OptionDefaults *disable_flag_override(bool value = true) {
        disable_flag_override_ = value;
        return this;
    }

    OptionDefaults *delimiter(char value = '\0') {
        delimiter_ = value;
        return this;
    }
};

class Option : public OptionBase<Option> {
    friend App;

  protected:

    std::vector<std::string> snames_{};

    std::vector<std::string> lnames_{};

    std::vector<std::pair<std::string, std::string>> default_flag_values_{};

    std::vector<std::string> fnames_{};

    std::string pname_{};

    std::string envname_{};


    std::string description_{};

    std::string default_str_{};

    std::string option_text_{};

    std::function<std::string()> type_name_{[]() { return std::string(); }};

    std::function<std::string()> default_function_{};


    int type_size_max_{1};
    int type_size_min_{1};

    int expected_min_{1};
    int expected_max_{1};

    std::vector<Validator> validators_{};

    std::set<Option *> needs_{};

    std::set<Option *> excludes_{};


    App *parent_{nullptr};

    callback_t callback_{};


    results_t results_{};
    results_t proc_results_{};
    enum class option_state : char {
        parsing = 0,       
        validated = 2,     
        reduced = 4,       
        callback_run = 6,  
    };
    option_state current_option_state_{option_state::parsing};
    bool allow_extra_args_{false};
    bool flag_like_{false};
    bool run_callback_for_default_{false};
    bool inject_separator_{false};
    bool trigger_on_result_{false};
    bool force_callback_{false};

    Option(std::string option_name, std::string option_description, callback_t callback, App *parent)
        : description_(std::move(option_description)), parent_(parent), callback_(std::move(callback)) {
        std::tie(snames_, lnames_, pname_) = detail::get_names(detail::split_names(option_name));
    }

  public:

    Option(const Option &) = delete;
    Option &operator=(const Option &) = delete;

    CLI11_NODISCARD std::size_t count() const { return results_.size(); }

    CLI11_NODISCARD bool empty() const { return results_.empty(); }

    explicit operator bool() const { return !empty() || force_callback_; }

    void clear() {
        results_.clear();
        current_option_state_ = option_state::parsing;
    }


    Option *expected(int value);

    Option *expected(int value_min, int value_max);

    Option *allow_extra_args(bool value = true) {
        allow_extra_args_ = value;
        return this;
    }
    CLI11_NODISCARD bool get_allow_extra_args() const { return allow_extra_args_; }
    Option *trigger_on_parse(bool value = true) {
        trigger_on_result_ = value;
        return this;
    }
    CLI11_NODISCARD bool get_trigger_on_parse() const { return trigger_on_result_; }

    Option *force_callback(bool value = true) {
        force_callback_ = value;
        return this;
    }
    CLI11_NODISCARD bool get_force_callback() const { return force_callback_; }

    Option *run_callback_for_default(bool value = true) {
        run_callback_for_default_ = value;
        return this;
    }
    CLI11_NODISCARD bool get_run_callback_for_default() const { return run_callback_for_default_; }

    Option *check(Validator validator, const std::string &validator_name = "");

    Option *check(std::function<std::string(const std::string &)> Validator,
                  std::string Validator_description = "",
                  std::string Validator_name = "");

    Option *transform(Validator Validator, const std::string &Validator_name = "");

    Option *transform(const std::function<std::string(std::string)> &func,
                      std::string transform_description = "",
                      std::string transform_name = "");

    Option *each(const std::function<void(std::string)> &func);

    Validator *get_validator(const std::string &Validator_name = "");

    Validator *get_validator(int index);

    Option *needs(Option *opt) {
        if(opt != this) {
            needs_.insert(opt);
        }
        return this;
    }

    template <typename T = App> Option *needs(std::string opt_name) {
        auto opt = static_cast<T *>(parent_)->get_option_no_throw(opt_name);
        if(opt == nullptr) {
            throw IncorrectConstruction::MissingOption(opt_name);
        }
        return needs(opt);
    }

    template <typename A, typename B, typename... ARG> Option *needs(A opt, B opt1, ARG... args) {
        needs(opt);
        return needs(opt1, args...);  // NOLINT(readability-suspicious-call-argument)
    }

    bool remove_needs(Option *opt);

    Option *excludes(Option *opt);

    template <typename T = App> Option *excludes(std::string opt_name) {
        auto opt = static_cast<T *>(parent_)->get_option_no_throw(opt_name);
        if(opt == nullptr) {
            throw IncorrectConstruction::MissingOption(opt_name);
        }
        return excludes(opt);
    }

    template <typename A, typename B, typename... ARG> Option *excludes(A opt, B opt1, ARG... args) {
        excludes(opt);
        return excludes(opt1, args...);
    }

    bool remove_excludes(Option *opt);

    Option *envname(std::string name) {
        envname_ = std::move(name);
        return this;
    }

    template <typename T = App> Option *ignore_case(bool value = true);

    template <typename T = App> Option *ignore_underscore(bool value = true);

    Option *multi_option_policy(MultiOptionPolicy value = MultiOptionPolicy::Throw);

    Option *disable_flag_override(bool value = true) {
        disable_flag_override_ = value;
        return this;
    }

    CLI11_NODISCARD int get_type_size() const { return type_size_min_; }

    CLI11_NODISCARD int get_type_size_min() const { return type_size_min_; }
    CLI11_NODISCARD int get_type_size_max() const { return type_size_max_; }

    CLI11_NODISCARD bool get_inject_separator() const { return inject_separator_; }

    CLI11_NODISCARD std::string get_envname() const { return envname_; }

    CLI11_NODISCARD std::set<Option *> get_needs() const { return needs_; }

    CLI11_NODISCARD std::set<Option *> get_excludes() const { return excludes_; }

    CLI11_NODISCARD std::string get_default_str() const { return default_str_; }

    CLI11_NODISCARD callback_t get_callback() const { return callback_; }

    CLI11_NODISCARD const std::vector<std::string> &get_lnames() const { return lnames_; }

    CLI11_NODISCARD const std::vector<std::string> &get_snames() const { return snames_; }

    CLI11_NODISCARD const std::vector<std::string> &get_fnames() const { return fnames_; }
    CLI11_NODISCARD const std::string &get_single_name() const {
        if(!lnames_.empty()) {
            return lnames_[0];
        }
        if(!pname_.empty()) {
            return pname_;
        }
        if(!snames_.empty()) {
            return snames_[0];
        }
        return envname_;
    }
    CLI11_NODISCARD int get_expected() const { return expected_min_; }

    CLI11_NODISCARD int get_expected_min() const { return expected_min_; }
    CLI11_NODISCARD int get_expected_max() const { return expected_max_; }

    CLI11_NODISCARD int get_items_expected_min() const { return type_size_min_ * expected_min_; }

    CLI11_NODISCARD int get_items_expected_max() const {
        int t = type_size_max_;
        return detail::checked_multiply(t, expected_max_) ? t : detail::expected_max_vector_size;
    }
    CLI11_NODISCARD int get_items_expected() const { return get_items_expected_min(); }

    CLI11_NODISCARD bool get_positional() const { return pname_.length() > 0; }

    CLI11_NODISCARD bool nonpositional() const { return (snames_.size() + lnames_.size()) > 0; }

    CLI11_NODISCARD bool has_description() const { return description_.length() > 0; }

    CLI11_NODISCARD const std::string &get_description() const { return description_; }

    Option *description(std::string option_description) {
        description_ = std::move(option_description);
        return this;
    }

    Option *option_text(std::string text) {
        option_text_ = std::move(text);
        return this;
    }

    CLI11_NODISCARD const std::string &get_option_text() const { return option_text_; }


    CLI11_NODISCARD std::string get_name(bool positional = false,  
                                         bool all_options = false  
    ) const;


    void run_callback();

    CLI11_NODISCARD const std::string &matching_name(const Option &other) const;

    bool operator==(const Option &other) const { return !matching_name(other).empty(); }

    CLI11_NODISCARD bool check_name(const std::string &name) const;

    CLI11_NODISCARD bool check_sname(std::string name) const {
        return (detail::find_member(std::move(name), snames_, ignore_case_) >= 0);
    }

    CLI11_NODISCARD bool check_lname(std::string name) const {
        return (detail::find_member(std::move(name), lnames_, ignore_case_, ignore_underscore_) >= 0);
    }

    CLI11_NODISCARD bool check_fname(std::string name) const {
        if(fnames_.empty()) {
            return false;
        }
        return (detail::find_member(std::move(name), fnames_, ignore_case_, ignore_underscore_) >= 0);
    }

    CLI11_NODISCARD std::string get_flag_value(const std::string &name, std::string input_value) const;

    Option *add_result(std::string s);

    Option *add_result(std::string s, int &results_added);

    Option *add_result(std::vector<std::string> s);

    CLI11_NODISCARD const results_t &results() const { return results_; }

    CLI11_NODISCARD results_t reduced_results() const;

    template <typename T> void results(T &output) const {
        bool retval = false;
        if(current_option_state_ >= option_state::reduced || (results_.size() == 1 && validators_.empty())) {
            const results_t &res = (proc_results_.empty()) ? results_ : proc_results_;
            retval = detail::lexical_conversion<T, T>(res, output);
        } else {
            results_t res;
            if(results_.empty()) {
                if(!default_str_.empty()) {
                    // _add_results takes an rvalue only
                    _add_result(std::string(default_str_), res);
                    _validate_results(res);
                    results_t extra;
                    _reduce_results(extra, res);
                    if(!extra.empty()) {
                        res = std::move(extra);
                    }
                } else {
                    res.emplace_back();
                }
            } else {
                res = reduced_results();
            }
            retval = detail::lexical_conversion<T, T>(res, output);
        }
        if(!retval) {
            throw ConversionError(get_name(), results_);
        }
    }

    template <typename T> CLI11_NODISCARD T as() const {
        T output;
        results(output);
        return output;
    }

    CLI11_NODISCARD bool get_callback_run() const { return (current_option_state_ == option_state::callback_run); }


    Option *type_name_fn(std::function<std::string()> typefun) {
        type_name_ = std::move(typefun);
        return this;
    }

    Option *type_name(std::string typeval) {
        type_name_fn([typeval]() { return typeval; });
        return this;
    }

    Option *type_size(int option_type_size);

    Option *type_size(int option_type_size_min, int option_type_size_max);

    void inject_separator(bool value = true) { inject_separator_ = value; }

    Option *default_function(const std::function<std::string()> &func) {
        default_function_ = func;
        return this;
    }

    Option *capture_default_str() {
        if(default_function_) {
            default_str_ = default_function_();
        }
        return this;
    }

    Option *default_str(std::string val) {
        default_str_ = std::move(val);
        return this;
    }

    template <typename X> Option *default_val(const X &val) {
        std::string val_str = detail::to_string(val);
        auto old_option_state = current_option_state_;
        results_t old_results{std::move(results_)};
        results_.clear();
        try {
            add_result(val_str);
            // if trigger_on_result_ is set the callback already ran
            if(run_callback_for_default_ && !trigger_on_result_) {
                run_callback();  // run callback sets the state, we need to reset it again
                current_option_state_ = option_state::parsing;
            } else {
                _validate_results(results_);
                current_option_state_ = old_option_state;
            }
        } catch(const CLI::Error &) {
            // this should be done
            results_ = std::move(old_results);
            current_option_state_ = old_option_state;
            throw;
        }
        results_ = std::move(old_results);
        default_str_ = std::move(val_str);
        return this;
    }

    CLI11_NODISCARD std::string get_type_name() const;

  private:
    void _validate_results(results_t &res) const;

    void _reduce_results(results_t &out, const results_t &original) const;

    // Run a result through the Validators
    std::string _validate(std::string &result, int index) const;

    int _add_result(std::string &&result, std::vector<std::string> &res) const;
};




template <typename CRTP> template <typename T> void OptionBase<CRTP>::copy_to(T *other) const {
    other->group(group_);
    other->required(required_);
    other->ignore_case(ignore_case_);
    other->ignore_underscore(ignore_underscore_);
    other->configurable(configurable_);
    other->disable_flag_override(disable_flag_override_);
    other->delimiter(delimiter_);
    other->always_capture_default(always_capture_default_);
    other->multi_option_policy(multi_option_policy_);
}

CLI11_INLINE Option *Option::expected(int value) {
    if(value < 0) {
        expected_min_ = -value;
        if(expected_max_ < expected_min_) {
            expected_max_ = expected_min_;
        }
        allow_extra_args_ = true;
        flag_like_ = false;
    } else if(value == detail::expected_max_vector_size) {
        expected_min_ = 1;
        expected_max_ = detail::expected_max_vector_size;
        allow_extra_args_ = true;
        flag_like_ = false;
    } else {
        expected_min_ = value;
        expected_max_ = value;
        flag_like_ = (expected_min_ == 0);
    }
    return this;
}

CLI11_INLINE Option *Option::expected(int value_min, int value_max) {
    if(value_min < 0) {
        value_min = -value_min;
    }

    if(value_max < 0) {
        value_max = detail::expected_max_vector_size;
    }
    if(value_max < value_min) {
        expected_min_ = value_max;
        expected_max_ = value_min;
    } else {
        expected_max_ = value_max;
        expected_min_ = value_min;
    }

    return this;
}

CLI11_INLINE Option *Option::check(Validator validator, const std::string &validator_name) {
    validator.non_modifying();
    validators_.push_back(std::move(validator));
    if(!validator_name.empty())
        validators_.back().name(validator_name);
    return this;
}

CLI11_INLINE Option *Option::check(std::function<std::string(const std::string &)> Validator,
                                   std::string Validator_description,
                                   std::string Validator_name) {
    validators_.emplace_back(Validator, std::move(Validator_description), std::move(Validator_name));
    validators_.back().non_modifying();
    return this;
}

CLI11_INLINE Option *Option::transform(Validator Validator, const std::string &Validator_name) {
    validators_.insert(validators_.begin(), std::move(Validator));
    if(!Validator_name.empty())
        validators_.front().name(Validator_name);
    return this;
}

CLI11_INLINE Option *Option::transform(const std::function<std::string(std::string)> &func,
                                       std::string transform_description,
                                       std::string transform_name) {
    validators_.insert(validators_.begin(),
                       Validator(
                           [func](std::string &val) {
                               val = func(val);
                               return std::string{};
                           },
                           std::move(transform_description),
                           std::move(transform_name)));

    return this;
}

CLI11_INLINE Option *Option::each(const std::function<void(std::string)> &func) {
    validators_.emplace_back(
        [func](std::string &inout) {
            func(inout);
            return std::string{};
        },
        std::string{});
    return this;
}

CLI11_INLINE Validator *Option::get_validator(const std::string &Validator_name) {
    for(auto &Validator : validators_) {
        if(Validator_name == Validator.get_name()) {
            return &Validator;
        }
    }
    if((Validator_name.empty()) && (!validators_.empty())) {
        return &(validators_.front());
    }
    throw OptionNotFound(std::string{"Validator "} + Validator_name + " Not Found");
}

CLI11_INLINE Validator *Option::get_validator(int index) {
    // This is an signed int so that it is not equivalent to a pointer.
    if(index >= 0 && index < static_cast<int>(validators_.size())) {
        return &(validators_[static_cast<decltype(validators_)::size_type>(index)]);
    }
    throw OptionNotFound("Validator index is not valid");
}

CLI11_INLINE bool Option::remove_needs(Option *opt) {
    auto iterator = std::find(std::begin(needs_), std::end(needs_), opt);

    if(iterator == std::end(needs_)) {
        return false;
    }
    needs_.erase(iterator);
    return true;
}

CLI11_INLINE Option *Option::excludes(Option *opt) {
    if(opt == this) {
        throw(IncorrectConstruction("and option cannot exclude itself"));
    }
    excludes_.insert(opt);

    // Help text should be symmetric - excluding a should exclude b
    opt->excludes_.insert(this);

    // Ignoring the insert return value, excluding twice is now allowed.
    // (Mostly to allow both directions to be excluded by user, even though the library does it for you.)

    return this;
}

CLI11_INLINE bool Option::remove_excludes(Option *opt) {
    auto iterator = std::find(std::begin(excludes_), std::end(excludes_), opt);

    if(iterator == std::end(excludes_)) {
        return false;
    }
    excludes_.erase(iterator);
    return true;
}

template <typename T> Option *Option::ignore_case(bool value) {
    if(!ignore_case_ && value) {
        ignore_case_ = value;
        auto *parent = static_cast<T *>(parent_);
        for(const Option_p &opt : parent->options_) {
            if(opt.get() == this) {
                continue;
            }
            const auto &omatch = opt->matching_name(*this);
            if(!omatch.empty()) {
                ignore_case_ = false;
                throw OptionAlreadyAdded("adding ignore case caused a name conflict with " + omatch);
            }
        }
    } else {
        ignore_case_ = value;
    }
    return this;
}

template <typename T> Option *Option::ignore_underscore(bool value) {

    if(!ignore_underscore_ && value) {
        ignore_underscore_ = value;
        auto *parent = static_cast<T *>(parent_);
        for(const Option_p &opt : parent->options_) {
            if(opt.get() == this) {
                continue;
            }
            const auto &omatch = opt->matching_name(*this);
            if(!omatch.empty()) {
                ignore_underscore_ = false;
                throw OptionAlreadyAdded("adding ignore underscore caused a name conflict with " + omatch);
            }
        }
    } else {
        ignore_underscore_ = value;
    }
    return this;
}

CLI11_INLINE Option *Option::multi_option_policy(MultiOptionPolicy value) {
    if(value != multi_option_policy_) {
        if(multi_option_policy_ == MultiOptionPolicy::Throw && expected_max_ == detail::expected_max_vector_size &&
           expected_min_ > 1) {  // this bizarre condition is to maintain backwards compatibility
                                 // with the previous behavior of expected_ with vectors
            expected_max_ = expected_min_;
        }
        multi_option_policy_ = value;
        current_option_state_ = option_state::parsing;
    }
    return this;
}

CLI11_NODISCARD CLI11_INLINE std::string Option::get_name(bool positional, bool all_options) const {
    if(get_group().empty())
        return {};  // Hidden

    if(all_options) {

        std::vector<std::string> name_list;

        if((positional && (!pname_.empty())) || (snames_.empty() && lnames_.empty())) {
            name_list.push_back(pname_);
        }
        if((get_items_expected() == 0) && (!fnames_.empty())) {
            for(const std::string &sname : snames_) {
                name_list.push_back("-" + sname);
                if(check_fname(sname)) {
                    name_list.back() += "{" + get_flag_value(sname, "") + "}";
                }
            }

            for(const std::string &lname : lnames_) {
                name_list.push_back("--" + lname);
                if(check_fname(lname)) {
                    name_list.back() += "{" + get_flag_value(lname, "") + "}";
                }
            }
        } else {
            for(const std::string &sname : snames_)
                name_list.push_back("-" + sname);

            for(const std::string &lname : lnames_)
                name_list.push_back("--" + lname);
        }

        return detail::join(name_list);
    }

    // This returns the positional name no matter what
    if(positional)
        return pname_;

    // Prefer long name
    if(!lnames_.empty())
        return std::string(2, '-') + lnames_[0];

    // Or short name if no long name
    if(!snames_.empty())
        return std::string(1, '-') + snames_[0];

    // If positional is the only name, it's okay to use that
    return pname_;
}

CLI11_INLINE void Option::run_callback() {
    if(force_callback_ && results_.empty()) {
        add_result(default_str_);
    }
    if(current_option_state_ == option_state::parsing) {
        _validate_results(results_);
        current_option_state_ = option_state::validated;
    }

    if(current_option_state_ < option_state::reduced) {
        _reduce_results(proc_results_, results_);
        current_option_state_ = option_state::reduced;
    }
    if(current_option_state_ >= option_state::reduced) {
        current_option_state_ = option_state::callback_run;
        if(!(callback_)) {
            return;
        }
        const results_t &send_results = proc_results_.empty() ? results_ : proc_results_;
        bool local_result = callback_(send_results);

        if(!local_result)
            throw ConversionError(get_name(), results_);
    }
}

CLI11_NODISCARD CLI11_INLINE const std::string &Option::matching_name(const Option &other) const {
    static const std::string estring;
    for(const std::string &sname : snames_)
        if(other.check_sname(sname))
            return sname;
    for(const std::string &lname : lnames_)
        if(other.check_lname(lname))
            return lname;

    if(ignore_case_ ||
       ignore_underscore_) {  // We need to do the inverse, in case we are ignore_case or ignore underscore
        for(const std::string &sname : other.snames_)
            if(check_sname(sname))
                return sname;
        for(const std::string &lname : other.lnames_)
            if(check_lname(lname))
                return lname;
    }
    return estring;
}

CLI11_NODISCARD CLI11_INLINE bool Option::check_name(const std::string &name) const {

    if(name.length() > 2 && name[0] == '-' && name[1] == '-')
        return check_lname(name.substr(2));
    if(name.length() > 1 && name.front() == '-')
        return check_sname(name.substr(1));
    if(!pname_.empty()) {
        std::string local_pname = pname_;
        std::string local_name = name;
        if(ignore_underscore_) {
            local_pname = detail::remove_underscore(local_pname);
            local_name = detail::remove_underscore(local_name);
        }
        if(ignore_case_) {
            local_pname = detail::to_lower(local_pname);
            local_name = detail::to_lower(local_name);
        }
        if(local_name == local_pname) {
            return true;
        }
    }

    if(!envname_.empty()) {
        // this needs to be the original since envname_ shouldn't match on case insensitivity
        return (name == envname_);
    }
    return false;
}

CLI11_NODISCARD CLI11_INLINE std::string Option::get_flag_value(const std::string &name,
                                                                std::string input_value) const {
    static const std::string trueString{"true"};
    static const std::string falseString{"false"};
    static const std::string emptyString{"{}"};
    // check for disable flag override_
    if(disable_flag_override_) {
        if(!((input_value.empty()) || (input_value == emptyString))) {
            auto default_ind = detail::find_member(name, fnames_, ignore_case_, ignore_underscore_);
            if(default_ind >= 0) {
                // We can static cast this to std::size_t because it is more than 0 in this block
                if(default_flag_values_[static_cast<std::size_t>(default_ind)].second != input_value) {
                    throw(ArgumentMismatch::FlagOverride(name));
                }
            } else {
                if(input_value != trueString) {
                    throw(ArgumentMismatch::FlagOverride(name));
                }
            }
        }
    }
    auto ind = detail::find_member(name, fnames_, ignore_case_, ignore_underscore_);
    if((input_value.empty()) || (input_value == emptyString)) {
        if(flag_like_) {
            return (ind < 0) ? trueString : default_flag_values_[static_cast<std::size_t>(ind)].second;
        }
        return (ind < 0) ? default_str_ : default_flag_values_[static_cast<std::size_t>(ind)].second;
    }
    if(ind < 0) {
        return input_value;
    }
    if(default_flag_values_[static_cast<std::size_t>(ind)].second == falseString) {
        try {
            auto val = detail::to_flag_value(input_value);
            return (val == 1) ? falseString : (val == (-1) ? trueString : std::to_string(-val));
        } catch(const std::invalid_argument &) {
            return input_value;
        }
    } else {
        return input_value;
    }
}

CLI11_INLINE Option *Option::add_result(std::string s) {
    _add_result(std::move(s), results_);
    current_option_state_ = option_state::parsing;
    return this;
}

CLI11_INLINE Option *Option::add_result(std::string s, int &results_added) {
    results_added = _add_result(std::move(s), results_);
    current_option_state_ = option_state::parsing;
    return this;
}

CLI11_INLINE Option *Option::add_result(std::vector<std::string> s) {
    current_option_state_ = option_state::parsing;
    for(auto &str : s) {
        _add_result(std::move(str), results_);
    }
    return this;
}

CLI11_NODISCARD CLI11_INLINE results_t Option::reduced_results() const {
    results_t res = proc_results_.empty() ? results_ : proc_results_;
    if(current_option_state_ < option_state::reduced) {
        if(current_option_state_ == option_state::parsing) {
            res = results_;
            _validate_results(res);
        }
        if(!res.empty()) {
            results_t extra;
            _reduce_results(extra, res);
            if(!extra.empty()) {
                res = std::move(extra);
            }
        }
    }
    return res;
}

CLI11_INLINE Option *Option::type_size(int option_type_size) {
    if(option_type_size < 0) {
        // this section is included for backwards compatibility
        type_size_max_ = -option_type_size;
        type_size_min_ = -option_type_size;
        expected_max_ = detail::expected_max_vector_size;
    } else {
        type_size_max_ = option_type_size;
        if(type_size_max_ < detail::expected_max_vector_size) {
            type_size_min_ = option_type_size;
        } else {
            inject_separator_ = true;
        }
        if(type_size_max_ == 0)
            required_ = false;
    }
    return this;
}

CLI11_INLINE Option *Option::type_size(int option_type_size_min, int option_type_size_max) {
    if(option_type_size_min < 0 || option_type_size_max < 0) {
        // this section is included for backwards compatibility
        expected_max_ = detail::expected_max_vector_size;
        option_type_size_min = (std::abs)(option_type_size_min);
        option_type_size_max = (std::abs)(option_type_size_max);
    }

    if(option_type_size_min > option_type_size_max) {
        type_size_max_ = option_type_size_min;
        type_size_min_ = option_type_size_max;
    } else {
        type_size_min_ = option_type_size_min;
        type_size_max_ = option_type_size_max;
    }
    if(type_size_max_ == 0) {
        required_ = false;
    }
    if(type_size_max_ >= detail::expected_max_vector_size) {
        inject_separator_ = true;
    }
    return this;
}

CLI11_NODISCARD CLI11_INLINE std::string Option::get_type_name() const {
    std::string full_type_name = type_name_();
    if(!validators_.empty()) {
        for(const auto &Validator : validators_) {
            std::string vtype = Validator.get_description();
            if(!vtype.empty()) {
                full_type_name += ":" + vtype;
            }
        }
    }
    return full_type_name;
}

CLI11_INLINE void Option::_validate_results(results_t &res) const {
    // Run the Validators (can change the string)
    if(!validators_.empty()) {
        if(type_size_max_ > 1) {  // in this context index refers to the index in the type
            int index = 0;
            if(get_items_expected_max() < static_cast<int>(res.size()) &&
               multi_option_policy_ == CLI::MultiOptionPolicy::TakeLast) {
                // create a negative index for the earliest ones
                index = get_items_expected_max() - static_cast<int>(res.size());
            }

            for(std::string &result : res) {
                if(detail::is_separator(result) && type_size_max_ != type_size_min_ && index >= 0) {
                    index = 0;  // reset index for variable size chunks
                    continue;
                }
                auto err_msg = _validate(result, (index >= 0) ? (index % type_size_max_) : index);
                if(!err_msg.empty())
                    throw ValidationError(get_name(), err_msg);
                ++index;
            }
        } else {
            int index = 0;
            if(expected_max_ < static_cast<int>(res.size()) &&
               multi_option_policy_ == CLI::MultiOptionPolicy::TakeLast) {
                // create a negative index for the earliest ones
                index = expected_max_ - static_cast<int>(res.size());
            }
            for(std::string &result : res) {
                auto err_msg = _validate(result, index);
                ++index;
                if(!err_msg.empty())
                    throw ValidationError(get_name(), err_msg);
            }
        }
    }
}

CLI11_INLINE void Option::_reduce_results(results_t &out, const results_t &original) const {

    // max num items expected or length of vector, always at least 1
    // Only valid for a trimming policy

    out.clear();
    // Operation depends on the policy setting
    switch(multi_option_policy_) {
    case MultiOptionPolicy::TakeAll:
        break;
    case MultiOptionPolicy::TakeLast: {
        // Allow multi-option sizes (including 0)
        std::size_t trim_size = std::min<std::size_t>(
            static_cast<std::size_t>(std::max<int>(get_items_expected_max(), 1)), original.size());
        if(original.size() != trim_size) {
            out.assign(original.end() - static_cast<results_t::difference_type>(trim_size), original.end());
        }
    } break;
    case MultiOptionPolicy::TakeFirst: {
        std::size_t trim_size = std::min<std::size_t>(
            static_cast<std::size_t>(std::max<int>(get_items_expected_max(), 1)), original.size());
        if(original.size() != trim_size) {
            out.assign(original.begin(), original.begin() + static_cast<results_t::difference_type>(trim_size));
        }
    } break;
    case MultiOptionPolicy::Join:
        if(results_.size() > 1) {
            out.push_back(detail::join(original, std::string(1, (delimiter_ == '\0') ? '\n' : delimiter_)));
        }
        break;
    case MultiOptionPolicy::Sum:
        out.push_back(detail::sum_string_vector(original));
        break;
    case MultiOptionPolicy::Throw:
    default: {
        auto num_min = static_cast<std::size_t>(get_items_expected_min());
        auto num_max = static_cast<std::size_t>(get_items_expected_max());
        if(num_min == 0) {
            num_min = 1;
        }
        if(num_max == 0) {
            num_max = 1;
        }
        if(original.size() < num_min) {
            throw ArgumentMismatch::AtLeast(get_name(), static_cast<int>(num_min), original.size());
        }
        if(original.size() > num_max) {
            throw ArgumentMismatch::AtMost(get_name(), static_cast<int>(num_max), original.size());
        }
        break;
    }
    }
    // this check is to allow an empty vector in certain circumstances but not if expected is not zero.
    // {} is the indicator for an empty container
    if(out.empty()) {
        if(original.size() == 1 && original[0] == "{}" && get_items_expected_min() > 0) {
            out.push_back("{}");
            out.push_back("%%");
        }
    } else if(out.size() == 1 && out[0] == "{}" && get_items_expected_min() > 0) {
        out.push_back("%%");
    }
}

CLI11_INLINE std::string Option::_validate(std::string &result, int index) const {
    std::string err_msg;
    if(result.empty() && expected_min_ == 0) {
        // an empty with nothing expected is allowed
        return err_msg;
    }
    for(const auto &vali : validators_) {
        auto v = vali.get_application_index();
        if(v == -1 || v == index) {
            try {
                err_msg = vali(result);
            } catch(const ValidationError &err) {
                err_msg = err.what();
            }
            if(!err_msg.empty())
                break;
        }
    }

    return err_msg;
}

CLI11_INLINE int Option::_add_result(std::string &&result, std::vector<std::string> &res) const {
    int result_count = 0;
    if(allow_extra_args_ && !result.empty() && result.front() == '[' &&
       result.back() == ']') {  // this is now a vector string likely from the default or user entry
        result.pop_back();

        for(auto &var : CLI::detail::split(result.substr(1), ',')) {
            if(!var.empty()) {
                result_count += _add_result(std::move(var), res);
            }
        }
        return result_count;
    }
    if(delimiter_ == '\0') {
        res.push_back(std::move(result));
        ++result_count;
    } else {
        if((result.find_first_of(delimiter_) != std::string::npos)) {
            for(const auto &var : CLI::detail::split(result, delimiter_)) {
                if(!var.empty()) {
                    res.push_back(var);
                    ++result_count;
                }
            }
        } else {
            res.push_back(std::move(result));
            ++result_count;
        }
    }
    return result_count;
}



#ifndef CLI11_PARSE
#define CLI11_PARSE(app, argc, argv)                                                                                   \
    try {                                                                                                              \
        (app).parse((argc), (argv));                                                                                   \
    } catch(const CLI::ParseError &e) {                                                                                \
        return (app).exit(e);                                                                                          \
    }
#endif

namespace detail {
enum class Classifier { NONE, POSITIONAL_MARK, SHORT, LONG, WINDOWS_STYLE, SUBCOMMAND, SUBCOMMAND_TERMINATOR };
struct AppFriend;
}  // namespace detail

namespace FailureMessage {
std::string simple(const App *app, const Error &e);
std::string help(const App *app, const Error &e);
}  // namespace FailureMessage


enum class config_extras_mode : char { error = 0, ignore, ignore_all, capture };

class App;

using App_p = std::shared_ptr<App>;

namespace detail {

template <typename T, enable_if_t<!std::is_integral<T>::value || (sizeof(T) <= 1U), detail::enabler> = detail::dummy>
Option *default_flag_modifiers(Option *opt) {
    return opt->always_capture_default();
}

template <typename T, enable_if_t<std::is_integral<T>::value && (sizeof(T) > 1U), detail::enabler> = detail::dummy>
Option *default_flag_modifiers(Option *opt) {
    return opt->multi_option_policy(MultiOptionPolicy::Sum)->default_str("0")->force_callback();
}

}  // namespace detail

class Option_group;

class App {
    friend Option;
    friend detail::AppFriend;

  protected:
    // This library follows the Google style guide for member names ending in underscores


    std::string name_{};

    std::string description_{};

    bool allow_extras_{false};

    config_extras_mode allow_config_extras_{config_extras_mode::ignore};

    bool prefix_command_{false};

    bool has_automatic_name_{false};

    bool required_{false};

    bool disabled_{false};

    bool pre_parse_called_{false};

    bool immediate_callback_{false};

    std::function<void(std::size_t)> pre_parse_callback_{};

    std::function<void()> parse_complete_callback_{};

    std::function<void()> final_callback_{};


    OptionDefaults option_defaults_{};

    std::vector<Option_p> options_{};


    std::string footer_{};

    std::function<std::string()> footer_callback_{};

    Option *help_ptr_{nullptr};

    Option *help_all_ptr_{nullptr};

    Option *version_ptr_{nullptr};

    std::shared_ptr<FormatterBase> formatter_{new Formatter()};

    std::function<std::string(const App *, const Error &e)> failure_message_{FailureMessage::simple};


    using missing_t = std::vector<std::pair<detail::Classifier, std::string>>;

    missing_t missing_{};

    std::vector<Option *> parse_order_{};

    std::vector<App *> parsed_subcommands_{};

    std::set<App *> exclude_subcommands_{};

    std::set<Option *> exclude_options_{};

    std::set<App *> need_subcommands_{};

    std::set<Option *> need_options_{};


    std::vector<App_p> subcommands_{};

    bool ignore_case_{false};

    bool ignore_underscore_{false};

    bool fallthrough_{false};

    bool allow_windows_style_options_{
#ifdef _WIN32
        true
#else
        false
#endif
    };
    bool positionals_at_end_{false};

    enum class startup_mode : char { stable, enabled, disabled };
    startup_mode default_startup{startup_mode::stable};

    bool configurable_{false};

    bool validate_positionals_{false};

    bool validate_optional_arguments_{false};

    bool silent_{false};

    std::uint32_t parsed_{0U};

    std::size_t require_subcommand_min_{0};

    std::size_t require_subcommand_max_{0};

    std::size_t require_option_min_{0};

    std::size_t require_option_max_{0};

    App *parent_{nullptr};

    std::string group_{"Subcommands"};

    std::vector<std::string> aliases_{};


    Option *config_ptr_{nullptr};

    std::shared_ptr<Config> config_formatter_{new ConfigTOML()};


    App(std::string app_description, std::string app_name, App *parent);

  public:

    explicit App(std::string app_description = "", std::string app_name = "")
        : App(app_description, app_name, nullptr) {
        set_help_flag("-h,--help", "Print this help message and exit");
    }

    App(const App &) = delete;
    App &operator=(const App &) = delete;

    virtual ~App() = default;

    App *callback(std::function<void()> app_callback) {
        if(immediate_callback_) {
            parse_complete_callback_ = std::move(app_callback);
        } else {
            final_callback_ = std::move(app_callback);
        }
        return this;
    }

    App *final_callback(std::function<void()> app_callback) {
        final_callback_ = std::move(app_callback);
        return this;
    }

    App *parse_complete_callback(std::function<void()> pc_callback) {
        parse_complete_callback_ = std::move(pc_callback);
        return this;
    }

    App *preparse_callback(std::function<void(std::size_t)> pp_callback) {
        pre_parse_callback_ = std::move(pp_callback);
        return this;
    }

    App *name(std::string app_name = "");

    App *alias(std::string app_name);

    App *allow_extras(bool allow = true) {
        allow_extras_ = allow;
        return this;
    }

    App *required(bool require = true) {
        required_ = require;
        return this;
    }

    App *disabled(bool disable = true) {
        disabled_ = disable;
        return this;
    }

    App *silent(bool silence = true) {
        silent_ = silence;
        return this;
    }

    App *disabled_by_default(bool disable = true) {
        if(disable) {
            default_startup = startup_mode::disabled;
        } else {
            default_startup = (default_startup == startup_mode::enabled) ? startup_mode::enabled : startup_mode::stable;
        }
        return this;
    }

    App *enabled_by_default(bool enable = true) {
        if(enable) {
            default_startup = startup_mode::enabled;
        } else {
            default_startup =
                (default_startup == startup_mode::disabled) ? startup_mode::disabled : startup_mode::stable;
        }
        return this;
    }

    App *immediate_callback(bool immediate = true);

    App *validate_positionals(bool validate = true) {
        validate_positionals_ = validate;
        return this;
    }

    App *validate_optional_arguments(bool validate = true) {
        validate_optional_arguments_ = validate;
        return this;
    }

    App *allow_config_extras(bool allow = true) {
        if(allow) {
            allow_config_extras_ = config_extras_mode::capture;
            allow_extras_ = true;
        } else {
            allow_config_extras_ = config_extras_mode::error;
        }
        return this;
    }

    App *allow_config_extras(config_extras_mode mode) {
        allow_config_extras_ = mode;
        return this;
    }

    App *prefix_command(bool allow = true) {
        prefix_command_ = allow;
        return this;
    }

    App *ignore_case(bool value = true);

    App *allow_windows_style_options(bool value = true) {
        allow_windows_style_options_ = value;
        return this;
    }

    App *positionals_at_end(bool value = true) {
        positionals_at_end_ = value;
        return this;
    }

    App *configurable(bool value = true) {
        configurable_ = value;
        return this;
    }

    App *ignore_underscore(bool value = true);

    App *formatter(std::shared_ptr<FormatterBase> fmt) {
        formatter_ = fmt;
        return this;
    }

    App *formatter_fn(std::function<std::string(const App *, std::string, AppFormatMode)> fmt) {
        formatter_ = std::make_shared<FormatterLambda>(fmt);
        return this;
    }

    App *config_formatter(std::shared_ptr<Config> fmt) {
        config_formatter_ = fmt;
        return this;
    }

    CLI11_NODISCARD bool parsed() const { return parsed_ > 0; }

    OptionDefaults *option_defaults() { return &option_defaults_; }


    Option *add_option(std::string option_name,
                       callback_t option_callback,
                       std::string option_description = "",
                       bool defaulted = false,
                       std::function<std::string()> func = {});

    template <typename AssignTo,
              typename ConvertTo = AssignTo,
              enable_if_t<!std::is_const<ConvertTo>::value, detail::enabler> = detail::dummy>
    Option *add_option(std::string option_name,
                       AssignTo &variable,  
                       std::string option_description = "") {

        auto fun = [&variable](const CLI::results_t &res) {  // comment for spacing
            return detail::lexical_conversion<AssignTo, ConvertTo>(res, variable);
        };

        Option *opt = add_option(option_name, fun, option_description, false, [&variable]() {
            return CLI::detail::checked_to_string<AssignTo, ConvertTo>(variable);
        });
        opt->type_name(detail::type_name<ConvertTo>());
        // these must be actual lvalues since (std::max) sometimes is defined in terms of references and references
        // to structs used in the evaluation can be temporary so that would cause issues.
        auto Tcount = detail::type_count<AssignTo>::value;
        auto XCcount = detail::type_count<ConvertTo>::value;
        opt->type_size(detail::type_count_min<ConvertTo>::value, (std::max)(Tcount, XCcount));
        opt->expected(detail::expected_count<ConvertTo>::value);
        opt->run_callback_for_default();
        return opt;
    }

    template <typename AssignTo, enable_if_t<!std::is_const<AssignTo>::value, detail::enabler> = detail::dummy>
    Option *add_option_no_stream(std::string option_name,
                                 AssignTo &variable,  
                                 std::string option_description = "") {

        auto fun = [&variable](const CLI::results_t &res) {  // comment for spacing
            return detail::lexical_conversion<AssignTo, AssignTo>(res, variable);
        };

        Option *opt = add_option(option_name, fun, option_description, false, []() { return std::string{}; });
        opt->type_name(detail::type_name<AssignTo>());
        opt->type_size(detail::type_count_min<AssignTo>::value, detail::type_count<AssignTo>::value);
        opt->expected(detail::expected_count<AssignTo>::value);
        opt->run_callback_for_default();
        return opt;
    }

    template <typename ArgType>
    Option *add_option_function(std::string option_name,
                                const std::function<void(const ArgType &)> &func,  
                                std::string option_description = "") {

        auto fun = [func](const CLI::results_t &res) {
            ArgType variable;
            bool result = detail::lexical_conversion<ArgType, ArgType>(res, variable);
            if(result) {
                func(variable);
            }
            return result;
        };

        Option *opt = add_option(option_name, std::move(fun), option_description, false);
        opt->type_name(detail::type_name<ArgType>());
        opt->type_size(detail::type_count_min<ArgType>::value, detail::type_count<ArgType>::value);
        opt->expected(detail::expected_count<ArgType>::value);
        return opt;
    }

    Option *add_option(std::string option_name) {
        return add_option(option_name, CLI::callback_t{}, std::string{}, false);
    }

    template <typename T,
              enable_if_t<std::is_const<T>::value && std::is_constructible<std::string, T>::value, detail::enabler> =
                  detail::dummy>
    Option *add_option(std::string option_name, T &option_description) {
        return add_option(option_name, CLI::callback_t(), option_description, false);
    }

    Option *set_help_flag(std::string flag_name = "", const std::string &help_description = "");

    Option *set_help_all_flag(std::string help_name = "", const std::string &help_description = "");

    Option *set_version_flag(std::string flag_name = "",
                             const std::string &versionString = "",
                             const std::string &version_help = "Display program version information and exit");

    Option *set_version_flag(std::string flag_name,
                             std::function<std::string()> vfunc,
                             const std::string &version_help = "Display program version information and exit");

  private:
    Option *_add_flag_internal(std::string flag_name, CLI::callback_t fun, std::string flag_description);

  public:
    Option *add_flag(std::string flag_name) { return _add_flag_internal(flag_name, CLI::callback_t(), std::string{}); }

    template <typename T,
              enable_if_t<std::is_const<T>::value && std::is_constructible<std::string, T>::value, detail::enabler> =
                  detail::dummy>
    Option *add_flag(std::string flag_name, T &flag_description) {
        return _add_flag_internal(flag_name, CLI::callback_t(), flag_description);
    }

    template <typename T,
              enable_if_t<!detail::is_mutable_container<T>::value && !std::is_const<T>::value &&
                              !std::is_constructible<std::function<void(int)>, T>::value,
                          detail::enabler> = detail::dummy>
    Option *add_flag(std::string flag_name,
                     T &flag_result,  
                     std::string flag_description = "") {

        CLI::callback_t fun = [&flag_result](const CLI::results_t &res) {
            return CLI::detail::lexical_cast(res[0], flag_result);
        };
        auto *opt = _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
        return detail::default_flag_modifiers<T>(opt);
    }

    template <typename T,
              enable_if_t<!std::is_assignable<std::function<void(std::int64_t)> &, T>::value, detail::enabler> =
                  detail::dummy>
    Option *add_flag(std::string flag_name,
                     std::vector<T> &flag_results,  
                     std::string flag_description = "") {
        CLI::callback_t fun = [&flag_results](const CLI::results_t &res) {
            bool retval = true;
            for(const auto &elem : res) {
                flag_results.emplace_back();
                retval &= detail::lexical_cast(elem, flag_results.back());
            }
            return retval;
        };
        return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description))
            ->multi_option_policy(MultiOptionPolicy::TakeAll)
            ->run_callback_for_default();
    }

    Option *add_flag_callback(std::string flag_name,
                              std::function<void(void)> function,  
                              std::string flag_description = "");

    Option *add_flag_function(std::string flag_name,
                              std::function<void(std::int64_t)> function,  
                              std::string flag_description = "");

#ifdef CLI11_CPP14
    Option *add_flag(std::string flag_name,
                     std::function<void(std::int64_t)> function,  
                     std::string flag_description = "") {
        return add_flag_function(std::move(flag_name), std::move(function), std::move(flag_description));
    }
#endif

    Option *set_config(std::string option_name = "",
                       std::string default_filename = "",
                       const std::string &help_message = "Read an ini file",
                       bool config_required = false);

    bool remove_option(Option *opt);

    template <typename T = Option_group>
    T *add_option_group(std::string group_name, std::string group_description = "") {
        if(!detail::valid_alias_name_string(group_name)) {
            throw IncorrectConstruction("option group names may not contain newlines or null characters");
        }
        auto option_group = std::make_shared<T>(std::move(group_description), group_name, this);
        auto *ptr = option_group.get();
        // move to App_p for overload resolution on older gcc versions
        App_p app_ptr = std::dynamic_pointer_cast<App>(option_group);
        add_subcommand(std::move(app_ptr));
        return ptr;
    }


    App *add_subcommand(std::string subcommand_name = "", std::string subcommand_description = "");

    App *add_subcommand(CLI::App_p subcom);

    bool remove_subcommand(App *subcom);

    App *get_subcommand(const App *subcom) const;

    CLI11_NODISCARD App *get_subcommand(std::string subcom) const;

    CLI11_NODISCARD App *get_subcommand(int index = 0) const;

    CLI::App_p get_subcommand_ptr(App *subcom) const;

    CLI11_NODISCARD CLI::App_p get_subcommand_ptr(std::string subcom) const;

    CLI11_NODISCARD CLI::App_p get_subcommand_ptr(int index = 0) const;

    CLI11_NODISCARD App *get_option_group(std::string group_name) const;

    CLI11_NODISCARD std::size_t count() const { return parsed_; }

    CLI11_NODISCARD std::size_t count_all() const;

    App *group(std::string group_name) {
        group_ = group_name;
        return this;
    }

    App *require_subcommand() {
        require_subcommand_min_ = 1;
        require_subcommand_max_ = 0;
        return this;
    }

    App *require_subcommand(int value) {
        if(value < 0) {
            require_subcommand_min_ = 0;
            require_subcommand_max_ = static_cast<std::size_t>(-value);
        } else {
            require_subcommand_min_ = static_cast<std::size_t>(value);
            require_subcommand_max_ = static_cast<std::size_t>(value);
        }
        return this;
    }

    App *require_subcommand(std::size_t min, std::size_t max) {
        require_subcommand_min_ = min;
        require_subcommand_max_ = max;
        return this;
    }

    App *require_option() {
        require_option_min_ = 1;
        require_option_max_ = 0;
        return this;
    }

    App *require_option(int value) {
        if(value < 0) {
            require_option_min_ = 0;
            require_option_max_ = static_cast<std::size_t>(-value);
        } else {
            require_option_min_ = static_cast<std::size_t>(value);
            require_option_max_ = static_cast<std::size_t>(value);
        }
        return this;
    }

    App *require_option(std::size_t min, std::size_t max) {
        require_option_min_ = min;
        require_option_max_ = max;
        return this;
    }

    App *fallthrough(bool value = true) {
        fallthrough_ = value;
        return this;
    }

    explicit operator bool() const { return parsed_ > 0; }


    virtual void pre_callback() {}

    //
    void clear();

    void parse(int argc, const char *const *argv);

    void parse(std::string commandline, bool program_name_included = false);

    void parse(std::vector<std::string> &args);

    void parse(std::vector<std::string> &&args);

    void parse_from_stream(std::istream &input);

    void failure_message(std::function<std::string(const App *, const Error &e)> function) {
        failure_message_ = function;
    }

    int exit(const Error &e, std::ostream &out = std::cout, std::ostream &err = std::cerr) const;


    CLI11_NODISCARD std::size_t count(std::string option_name) const { return get_option(option_name)->count(); }

    CLI11_NODISCARD std::vector<App *> get_subcommands() const { return parsed_subcommands_; }

    std::vector<const App *> get_subcommands(const std::function<bool(const App *)> &filter) const;

    std::vector<App *> get_subcommands(const std::function<bool(App *)> &filter);

    bool got_subcommand(const App *subcom) const {
        // get subcom needed to verify that this was a real subcommand
        return get_subcommand(subcom)->parsed_ > 0;
    }

    CLI11_NODISCARD bool got_subcommand(std::string subcommand_name) const {
        return get_subcommand(subcommand_name)->parsed_ > 0;
    }

    App *excludes(Option *opt) {
        if(opt == nullptr) {
            throw OptionNotFound("nullptr passed");
        }
        exclude_options_.insert(opt);
        return this;
    }

    App *excludes(App *app) {
        if(app == nullptr) {
            throw OptionNotFound("nullptr passed");
        }
        if(app == this) {
            throw OptionNotFound("cannot self reference in needs");
        }
        auto res = exclude_subcommands_.insert(app);
        // subcommand exclusion should be symmetric
        if(res.second) {
            app->exclude_subcommands_.insert(this);
        }
        return this;
    }

    App *needs(Option *opt) {
        if(opt == nullptr) {
            throw OptionNotFound("nullptr passed");
        }
        need_options_.insert(opt);
        return this;
    }

    App *needs(App *app) {
        if(app == nullptr) {
            throw OptionNotFound("nullptr passed");
        }
        if(app == this) {
            throw OptionNotFound("cannot self reference in needs");
        }
        need_subcommands_.insert(app);
        return this;
    }

    bool remove_excludes(Option *opt);

    bool remove_excludes(App *app);

    bool remove_needs(Option *opt);

    bool remove_needs(App *app);

    App *footer(std::string footer_string) {
        footer_ = std::move(footer_string);
        return this;
    }
    App *footer(std::function<std::string()> footer_function) {
        footer_callback_ = std::move(footer_function);
        return this;
    }
    CLI11_NODISCARD std::string config_to_str(bool default_also = false, bool write_description = false) const {
        return config_formatter_->to_config(this, default_also, write_description, "");
    }

    CLI11_NODISCARD std::string help(std::string prev = "", AppFormatMode mode = AppFormatMode::Normal) const;

    CLI11_NODISCARD std::string version() const;

    CLI11_NODISCARD std::shared_ptr<FormatterBase> get_formatter() const { return formatter_; }

    CLI11_NODISCARD std::shared_ptr<Config> get_config_formatter() const { return config_formatter_; }

    CLI11_NODISCARD std::shared_ptr<ConfigBase> get_config_formatter_base() const {
        // This is safer as a dynamic_cast if we have RTTI, as Config -> ConfigBase
#if CLI11_USE_STATIC_RTTI == 0
        return std::dynamic_pointer_cast<ConfigBase>(config_formatter_);
#else
        return std::static_pointer_cast<ConfigBase>(config_formatter_);
#endif
    }

    CLI11_NODISCARD std::string get_description() const { return description_; }

    App *description(std::string app_description) {
        description_ = std::move(app_description);
        return this;
    }

    std::vector<const Option *> get_options(const std::function<bool(const Option *)> filter = {}) const;

    std::vector<Option *> get_options(const std::function<bool(Option *)> filter = {});

    Option *get_option_no_throw(std::string option_name) noexcept;

    CLI11_NODISCARD const Option *get_option_no_throw(std::string option_name) const noexcept;

    CLI11_NODISCARD const Option *get_option(std::string option_name) const {
        const auto *opt = get_option_no_throw(option_name);
        if(opt == nullptr) {
            throw OptionNotFound(option_name);
        }
        return opt;
    }

    Option *get_option(std::string option_name) {
        auto *opt = get_option_no_throw(option_name);
        if(opt == nullptr) {
            throw OptionNotFound(option_name);
        }
        return opt;
    }

    const Option *operator[](const std::string &option_name) const { return get_option(option_name); }

    const Option *operator[](const char *option_name) const { return get_option(option_name); }

    CLI11_NODISCARD bool get_ignore_case() const { return ignore_case_; }

    CLI11_NODISCARD bool get_ignore_underscore() const { return ignore_underscore_; }

    CLI11_NODISCARD bool get_fallthrough() const { return fallthrough_; }

    CLI11_NODISCARD bool get_allow_windows_style_options() const { return allow_windows_style_options_; }

    CLI11_NODISCARD bool get_positionals_at_end() const { return positionals_at_end_; }

    CLI11_NODISCARD bool get_configurable() const { return configurable_; }

    CLI11_NODISCARD const std::string &get_group() const { return group_; }

    CLI11_NODISCARD std::string get_footer() const {
        return (footer_callback_) ? footer_callback_() + '\n' + footer_ : footer_;
    }

    CLI11_NODISCARD std::size_t get_require_subcommand_min() const { return require_subcommand_min_; }

    CLI11_NODISCARD std::size_t get_require_subcommand_max() const { return require_subcommand_max_; }

    CLI11_NODISCARD std::size_t get_require_option_min() const { return require_option_min_; }

    CLI11_NODISCARD std::size_t get_require_option_max() const { return require_option_max_; }

    CLI11_NODISCARD bool get_prefix_command() const { return prefix_command_; }

    CLI11_NODISCARD bool get_allow_extras() const { return allow_extras_; }

    CLI11_NODISCARD bool get_required() const { return required_; }

    CLI11_NODISCARD bool get_disabled() const { return disabled_; }

    CLI11_NODISCARD bool get_silent() const { return silent_; }

    CLI11_NODISCARD bool get_immediate_callback() const { return immediate_callback_; }

    CLI11_NODISCARD bool get_disabled_by_default() const { return (default_startup == startup_mode::disabled); }

    CLI11_NODISCARD bool get_enabled_by_default() const { return (default_startup == startup_mode::enabled); }
    CLI11_NODISCARD bool get_validate_positionals() const { return validate_positionals_; }
    CLI11_NODISCARD bool get_validate_optional_arguments() const { return validate_optional_arguments_; }

    CLI11_NODISCARD config_extras_mode get_allow_config_extras() const { return allow_config_extras_; }

    Option *get_help_ptr() { return help_ptr_; }

    CLI11_NODISCARD const Option *get_help_ptr() const { return help_ptr_; }

    CLI11_NODISCARD const Option *get_help_all_ptr() const { return help_all_ptr_; }

    Option *get_config_ptr() { return config_ptr_; }

    CLI11_NODISCARD const Option *get_config_ptr() const { return config_ptr_; }

    Option *get_version_ptr() { return version_ptr_; }

    CLI11_NODISCARD const Option *get_version_ptr() const { return version_ptr_; }

    App *get_parent() { return parent_; }

    CLI11_NODISCARD const App *get_parent() const { return parent_; }

    CLI11_NODISCARD const std::string &get_name() const { return name_; }

    CLI11_NODISCARD const std::vector<std::string> &get_aliases() const { return aliases_; }

    App *clear_aliases() {
        aliases_.clear();
        return this;
    }

    CLI11_NODISCARD std::string get_display_name(bool with_aliases = false) const;

    CLI11_NODISCARD bool check_name(std::string name_to_check) const;

    CLI11_NODISCARD std::vector<std::string> get_groups() const;

    CLI11_NODISCARD const std::vector<Option *> &parse_order() const { return parse_order_; }

    CLI11_NODISCARD std::vector<std::string> remaining(bool recurse = false) const;

    CLI11_NODISCARD std::vector<std::string> remaining_for_passthrough(bool recurse = false) const;

    CLI11_NODISCARD std::size_t remaining_size(bool recurse = false) const;


  protected:
    void _validate() const;

    void _configure();

    void run_callback(bool final_mode = false, bool suppress_final_callback = false);

    CLI11_NODISCARD bool _valid_subcommand(const std::string &current, bool ignore_used = true) const;

    CLI11_NODISCARD detail::Classifier _recognize(const std::string &current,
                                                  bool ignore_used_subcommands = true) const;

    // The parse function is now broken into several parts, and part of process

    void _process_config_file();

    void _process_env();

    void _process_callbacks();

    void _process_help_flags(bool trigger_help = false, bool trigger_all_help = false) const;

    void _process_requirements();

    void _process();

    void _process_extras();

    void _process_extras(std::vector<std::string> &args);

    void increment_parsed();

    void _parse(std::vector<std::string> &args);

    void _parse(std::vector<std::string> &&args);

    void _parse_stream(std::istream &input);

    void _parse_config(const std::vector<ConfigItem> &args);

    bool _parse_single_config(const ConfigItem &item, std::size_t level = 0);

    bool _parse_single(std::vector<std::string> &args, bool &positional_only);

    CLI11_NODISCARD std::size_t _count_remaining_positionals(bool required_only = false) const;

    CLI11_NODISCARD bool _has_remaining_positionals() const;

    bool _parse_positional(std::vector<std::string> &args, bool haltOnSubcommand);

    CLI11_NODISCARD App *
    _find_subcommand(const std::string &subc_name, bool ignore_disabled, bool ignore_used) const noexcept;

    bool _parse_subcommand(std::vector<std::string> &args);

    bool _parse_arg(std::vector<std::string> &args, detail::Classifier current_type);

    void _trigger_pre_parse(std::size_t remaining_args);

    App *_get_fallthrough_parent();

    CLI11_NODISCARD const std::string &_compare_subcommand_names(const App &subcom, const App &base) const;

    void _move_to_missing(detail::Classifier val_type, const std::string &val);

  public:
    void _move_option(Option *opt, App *app);
};  // namespace CLI

class Option_group : public App {
  public:
    Option_group(std::string group_description, std::string group_name, App *parent)
        : App(std::move(group_description), "", parent) {
        group(group_name);
        // option groups should have automatic fallthrough
    }
    using App::add_option;
    Option *add_option(Option *opt) {
        if(get_parent() == nullptr) {
            throw OptionNotFound("Unable to locate the specified option");
        }
        get_parent()->_move_option(opt, this);
        return opt;
    }
    void add_options(Option *opt) { add_option(opt); }
    template <typename... Args> void add_options(Option *opt, Args... args) {
        add_option(opt);
        add_options(args...);
    }
    using App::add_subcommand;
    App *add_subcommand(App *subcom) {
        App_p subc = subcom->get_parent()->get_subcommand_ptr(subcom);
        subc->get_parent()->remove_subcommand(subcom);
        add_subcommand(std::move(subc));
        return subcom;
    }
};

CLI11_INLINE void TriggerOn(App *trigger_app, App *app_to_enable);

CLI11_INLINE void TriggerOn(App *trigger_app, std::vector<App *> apps_to_enable);

CLI11_INLINE void TriggerOff(App *trigger_app, App *app_to_enable);

CLI11_INLINE void TriggerOff(App *trigger_app, std::vector<App *> apps_to_enable);

CLI11_INLINE void deprecate_option(Option *opt, const std::string &replacement = "");

inline void deprecate_option(App *app, const std::string &option_name, const std::string &replacement = "") {
    auto *opt = app->get_option(option_name);
    deprecate_option(opt, replacement);
}

inline void deprecate_option(App &app, const std::string &option_name, const std::string &replacement = "") {
    auto *opt = app.get_option(option_name);
    deprecate_option(opt, replacement);
}

CLI11_INLINE void retire_option(App *app, Option *opt);

CLI11_INLINE void retire_option(App &app, Option *opt);

CLI11_INLINE void retire_option(App *app, const std::string &option_name);

CLI11_INLINE void retire_option(App &app, const std::string &option_name);

namespace FailureMessage {

CLI11_INLINE std::string simple(const App *app, const Error &e);

CLI11_INLINE std::string help(const App *app, const Error &e);

}  // namespace FailureMessage

namespace detail {
struct AppFriend {
#ifdef CLI11_CPP14

    template <typename... Args> static decltype(auto) parse_arg(App *app, Args &&...args) {
        return app->_parse_arg(std::forward<Args>(args)...);
    }

    template <typename... Args> static decltype(auto) parse_subcommand(App *app, Args &&...args) {
        return app->_parse_subcommand(std::forward<Args>(args)...);
    }
#else
    template <typename... Args>
    static auto parse_arg(App *app, Args &&...args) ->
        typename std::result_of<decltype (&App::_parse_arg)(App, Args...)>::type {
        return app->_parse_arg(std::forward<Args>(args)...);
    }

    template <typename... Args>
    static auto parse_subcommand(App *app, Args &&...args) ->
        typename std::result_of<decltype (&App::_parse_subcommand)(App, Args...)>::type {
        return app->_parse_subcommand(std::forward<Args>(args)...);
    }
#endif
    static App *get_fallthrough_parent(App *app) { return app->_get_fallthrough_parent(); }
};
}  // namespace detail




CLI11_INLINE App::App(std::string app_description, std::string app_name, App *parent)
    : name_(std::move(app_name)), description_(std::move(app_description)), parent_(parent) {
    // Inherit if not from a nullptr
    if(parent_ != nullptr) {
        if(parent_->help_ptr_ != nullptr)
            set_help_flag(parent_->help_ptr_->get_name(false, true), parent_->help_ptr_->get_description());
        if(parent_->help_all_ptr_ != nullptr)
            set_help_all_flag(parent_->help_all_ptr_->get_name(false, true), parent_->help_all_ptr_->get_description());

        option_defaults_ = parent_->option_defaults_;

        // INHERITABLE
        failure_message_ = parent_->failure_message_;
        allow_extras_ = parent_->allow_extras_;
        allow_config_extras_ = parent_->allow_config_extras_;
        prefix_command_ = parent_->prefix_command_;
        immediate_callback_ = parent_->immediate_callback_;
        ignore_case_ = parent_->ignore_case_;
        ignore_underscore_ = parent_->ignore_underscore_;
        fallthrough_ = parent_->fallthrough_;
        validate_positionals_ = parent_->validate_positionals_;
        validate_optional_arguments_ = parent_->validate_optional_arguments_;
        configurable_ = parent_->configurable_;
        allow_windows_style_options_ = parent_->allow_windows_style_options_;
        group_ = parent_->group_;
        footer_ = parent_->footer_;
        formatter_ = parent_->formatter_;
        config_formatter_ = parent_->config_formatter_;
        require_subcommand_max_ = parent_->require_subcommand_max_;
    }
}

CLI11_INLINE App *App::name(std::string app_name) {

    if(parent_ != nullptr) {
        auto oname = name_;
        name_ = app_name;
        const auto &res = _compare_subcommand_names(*this, *_get_fallthrough_parent());
        if(!res.empty()) {
            name_ = oname;
            throw(OptionAlreadyAdded(app_name + " conflicts with existing subcommand names"));
        }
    } else {
        name_ = app_name;
    }
    has_automatic_name_ = false;
    return this;
}

CLI11_INLINE App *App::alias(std::string app_name) {
    if(app_name.empty() || !detail::valid_alias_name_string(app_name)) {
        throw IncorrectConstruction("Aliases may not be empty or contain newlines or null characters");
    }
    if(parent_ != nullptr) {
        aliases_.push_back(app_name);
        const auto &res = _compare_subcommand_names(*this, *_get_fallthrough_parent());
        if(!res.empty()) {
            aliases_.pop_back();
            throw(OptionAlreadyAdded("alias already matches an existing subcommand: " + app_name));
        }
    } else {
        aliases_.push_back(app_name);
    }

    return this;
}

CLI11_INLINE App *App::immediate_callback(bool immediate) {
    immediate_callback_ = immediate;
    if(immediate_callback_) {
        if(final_callback_ && !(parse_complete_callback_)) {
            std::swap(final_callback_, parse_complete_callback_);
        }
    } else if(!(final_callback_) && parse_complete_callback_) {
        std::swap(final_callback_, parse_complete_callback_);
    }
    return this;
}

CLI11_INLINE App *App::ignore_case(bool value) {
    if(value && !ignore_case_) {
        ignore_case_ = true;
        auto *p = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
        const auto &match = _compare_subcommand_names(*this, *p);
        if(!match.empty()) {
            ignore_case_ = false;  // we are throwing so need to be exception invariant
            throw OptionAlreadyAdded("ignore case would cause subcommand name conflicts: " + match);
        }
    }
    ignore_case_ = value;
    return this;
}

CLI11_INLINE App *App::ignore_underscore(bool value) {
    if(value && !ignore_underscore_) {
        ignore_underscore_ = true;
        auto *p = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
        const auto &match = _compare_subcommand_names(*this, *p);
        if(!match.empty()) {
            ignore_underscore_ = false;
            throw OptionAlreadyAdded("ignore underscore would cause subcommand name conflicts: " + match);
        }
    }
    ignore_underscore_ = value;
    return this;
}

CLI11_INLINE Option *App::add_option(std::string option_name,
                                     callback_t option_callback,
                                     std::string option_description,
                                     bool defaulted,
                                     std::function<std::string()> func) {
    Option myopt{option_name, option_description, option_callback, this};

    if(std::find_if(std::begin(options_), std::end(options_), [&myopt](const Option_p &v) { return *v == myopt; }) ==
       std::end(options_)) {
        options_.emplace_back();
        Option_p &option = options_.back();
        option.reset(new Option(option_name, option_description, option_callback, this));

        // Set the default string capture function
        option->default_function(func);

        // For compatibility with CLI11 1.7 and before, capture the default string here
        if(defaulted)
            option->capture_default_str();

        // Transfer defaults to the new option
        option_defaults_.copy_to(option.get());

        // Don't bother to capture if we already did
        if(!defaulted && option->get_always_capture_default())
            option->capture_default_str();

        return option.get();
    }
    // we know something matches now find what it is so we can produce more error information
    for(auto &opt : options_) {
        const auto &matchname = opt->matching_name(myopt);
        if(!matchname.empty()) {
            throw(OptionAlreadyAdded("added option matched existing option name: " + matchname));
        }
    }
    // this line should not be reached the above loop should trigger the throw
    throw(OptionAlreadyAdded("added option matched existing option name"));  // LCOV_EXCL_LINE
}

CLI11_INLINE Option *App::set_help_flag(std::string flag_name, const std::string &help_description) {
    // take flag_description by const reference otherwise add_flag tries to assign to help_description
    if(help_ptr_ != nullptr) {
        remove_option(help_ptr_);
        help_ptr_ = nullptr;
    }

    // Empty name will simply remove the help flag
    if(!flag_name.empty()) {
        help_ptr_ = add_flag(flag_name, help_description);
        help_ptr_->configurable(false);
    }

    return help_ptr_;
}

CLI11_INLINE Option *App::set_help_all_flag(std::string help_name, const std::string &help_description) {
    // take flag_description by const reference otherwise add_flag tries to assign to flag_description
    if(help_all_ptr_ != nullptr) {
        remove_option(help_all_ptr_);
        help_all_ptr_ = nullptr;
    }

    // Empty name will simply remove the help all flag
    if(!help_name.empty()) {
        help_all_ptr_ = add_flag(help_name, help_description);
        help_all_ptr_->configurable(false);
    }

    return help_all_ptr_;
}

CLI11_INLINE Option *
App::set_version_flag(std::string flag_name, const std::string &versionString, const std::string &version_help) {
    // take flag_description by const reference otherwise add_flag tries to assign to version_description
    if(version_ptr_ != nullptr) {
        remove_option(version_ptr_);
        version_ptr_ = nullptr;
    }

    // Empty name will simply remove the version flag
    if(!flag_name.empty()) {
        version_ptr_ = add_flag_callback(
            flag_name, [versionString]() { throw(CLI::CallForVersion(versionString, 0)); }, version_help);
        version_ptr_->configurable(false);
    }

    return version_ptr_;
}

CLI11_INLINE Option *
App::set_version_flag(std::string flag_name, std::function<std::string()> vfunc, const std::string &version_help) {
    if(version_ptr_ != nullptr) {
        remove_option(version_ptr_);
        version_ptr_ = nullptr;
    }

    // Empty name will simply remove the version flag
    if(!flag_name.empty()) {
        version_ptr_ = add_flag_callback(
            flag_name, [vfunc]() { throw(CLI::CallForVersion(vfunc(), 0)); }, version_help);
        version_ptr_->configurable(false);
    }

    return version_ptr_;
}

CLI11_INLINE Option *App::_add_flag_internal(std::string flag_name, CLI::callback_t fun, std::string flag_description) {
    Option *opt = nullptr;
    if(detail::has_default_flag_values(flag_name)) {
        // check for default values and if it has them
        auto flag_defaults = detail::get_default_flag_values(flag_name);
        detail::remove_default_flag_values(flag_name);
        opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
        for(const auto &fname : flag_defaults)
            opt->fnames_.push_back(fname.first);
        opt->default_flag_values_ = std::move(flag_defaults);
    } else {
        opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
    }
    // flags cannot have positional values
    if(opt->get_positional()) {
        auto pos_name = opt->get_name(true);
        remove_option(opt);
        throw IncorrectConstruction::PositionalFlag(pos_name);
    }
    opt->multi_option_policy(MultiOptionPolicy::TakeLast);
    opt->expected(0);
    opt->required(false);
    return opt;
}

CLI11_INLINE Option *App::add_flag_callback(std::string flag_name,
                                            std::function<void(void)> function,  
                                            std::string flag_description) {

    CLI::callback_t fun = [function](const CLI::results_t &res) {
        bool trigger{false};
        auto result = CLI::detail::lexical_cast(res[0], trigger);
        if(result && trigger) {
            function();
        }
        return result;
    };
    return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
}

CLI11_INLINE Option *
App::add_flag_function(std::string flag_name,
                       std::function<void(std::int64_t)> function,  
                       std::string flag_description) {

    CLI::callback_t fun = [function](const CLI::results_t &res) {
        std::int64_t flag_count{0};
        CLI::detail::lexical_cast(res[0], flag_count);
        function(flag_count);
        return true;
    };
    return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description))
        ->multi_option_policy(MultiOptionPolicy::Sum);
}

CLI11_INLINE Option *App::set_config(std::string option_name,
                                     std::string default_filename,
                                     const std::string &help_message,
                                     bool config_required) {

    // Remove existing config if present
    if(config_ptr_ != nullptr) {
        remove_option(config_ptr_);
        config_ptr_ = nullptr;  // need to remove the config_ptr completely
    }

    // Only add config if option passed
    if(!option_name.empty()) {
        config_ptr_ = add_option(option_name, help_message);
        if(config_required) {
            config_ptr_->required();
        }
        if(!default_filename.empty()) {
            config_ptr_->default_str(std::move(default_filename));
        }
        config_ptr_->configurable(false);
    }

    return config_ptr_;
}

CLI11_INLINE bool App::remove_option(Option *opt) {
    // Make sure no links exist
    for(Option_p &op : options_) {
        op->remove_needs(opt);
        op->remove_excludes(opt);
    }

    if(help_ptr_ == opt)
        help_ptr_ = nullptr;
    if(help_all_ptr_ == opt)
        help_all_ptr_ = nullptr;

    auto iterator =
        std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
    if(iterator != std::end(options_)) {
        options_.erase(iterator);
        return true;
    }
    return false;
}

CLI11_INLINE App *App::add_subcommand(std::string subcommand_name, std::string subcommand_description) {
    if(!subcommand_name.empty() && !detail::valid_name_string(subcommand_name)) {
        if(!detail::valid_first_char(subcommand_name[0])) {
            throw IncorrectConstruction("Subcommand name starts with invalid character, '!' and '-' are not allowed");
        }
        for(auto c : subcommand_name) {
            if(!detail::valid_later_char(c)) {
                throw IncorrectConstruction(std::string("Subcommand name contains invalid character ('") + c +
                                            "'), all characters are allowed except"
                                            "'=',':','{','}', and ' '");
            }
        }
    }
    CLI::App_p subcom = std::shared_ptr<App>(new App(std::move(subcommand_description), subcommand_name, this));
    return add_subcommand(std::move(subcom));
}

CLI11_INLINE App *App::add_subcommand(CLI::App_p subcom) {
    if(!subcom)
        throw IncorrectConstruction("passed App is not valid");
    auto *ckapp = (name_.empty() && parent_ != nullptr) ? _get_fallthrough_parent() : this;
    const auto &mstrg = _compare_subcommand_names(*subcom, *ckapp);
    if(!mstrg.empty()) {
        throw(OptionAlreadyAdded("subcommand name or alias matches existing subcommand: " + mstrg));
    }
    subcom->parent_ = this;
    subcommands_.push_back(std::move(subcom));
    return subcommands_.back().get();
}

CLI11_INLINE bool App::remove_subcommand(App *subcom) {
    // Make sure no links exist
    for(App_p &sub : subcommands_) {
        sub->remove_excludes(subcom);
        sub->remove_needs(subcom);
    }

    auto iterator = std::find_if(
        std::begin(subcommands_), std::end(subcommands_), [subcom](const App_p &v) { return v.get() == subcom; });
    if(iterator != std::end(subcommands_)) {
        subcommands_.erase(iterator);
        return true;
    }
    return false;
}

CLI11_INLINE App *App::get_subcommand(const App *subcom) const {
    if(subcom == nullptr)
        throw OptionNotFound("nullptr passed");
    for(const App_p &subcomptr : subcommands_)
        if(subcomptr.get() == subcom)
            return subcomptr.get();
    throw OptionNotFound(subcom->get_name());
}

CLI11_NODISCARD CLI11_INLINE App *App::get_subcommand(std::string subcom) const {
    auto *subc = _find_subcommand(subcom, false, false);
    if(subc == nullptr)
        throw OptionNotFound(subcom);
    return subc;
}

CLI11_NODISCARD CLI11_INLINE App *App::get_subcommand(int index) const {
    if(index >= 0) {
        auto uindex = static_cast<unsigned>(index);
        if(uindex < subcommands_.size())
            return subcommands_[uindex].get();
    }
    throw OptionNotFound(std::to_string(index));
}

CLI11_INLINE CLI::App_p App::get_subcommand_ptr(App *subcom) const {
    if(subcom == nullptr)
        throw OptionNotFound("nullptr passed");
    for(const App_p &subcomptr : subcommands_)
        if(subcomptr.get() == subcom)
            return subcomptr;
    throw OptionNotFound(subcom->get_name());
}

CLI11_NODISCARD CLI11_INLINE CLI::App_p App::get_subcommand_ptr(std::string subcom) const {
    for(const App_p &subcomptr : subcommands_)
        if(subcomptr->check_name(subcom))
            return subcomptr;
    throw OptionNotFound(subcom);
}

CLI11_NODISCARD CLI11_INLINE CLI::App_p App::get_subcommand_ptr(int index) const {
    if(index >= 0) {
        auto uindex = static_cast<unsigned>(index);
        if(uindex < subcommands_.size())
            return subcommands_[uindex];
    }
    throw OptionNotFound(std::to_string(index));
}

CLI11_NODISCARD CLI11_INLINE CLI::App *App::get_option_group(std::string group_name) const {
    for(const App_p &app : subcommands_) {
        if(app->name_.empty() && app->group_ == group_name) {
            return app.get();
        }
    }
    throw OptionNotFound(group_name);
}

CLI11_NODISCARD CLI11_INLINE std::size_t App::count_all() const {
    std::size_t cnt{0};
    for(const auto &opt : options_) {
        cnt += opt->count();
    }
    for(const auto &sub : subcommands_) {
        cnt += sub->count_all();
    }
    if(!get_name().empty()) {  // for named subcommands add the number of times the subcommand was called
        cnt += parsed_;
    }
    return cnt;
}

CLI11_INLINE void App::clear() {

    parsed_ = 0;
    pre_parse_called_ = false;

    missing_.clear();
    parsed_subcommands_.clear();
    for(const Option_p &opt : options_) {
        opt->clear();
    }
    for(const App_p &subc : subcommands_) {
        subc->clear();
    }
}

CLI11_INLINE void App::parse(int argc, const char *const *argv) {
    // If the name is not set, read from command line
    if(name_.empty() || has_automatic_name_) {
        has_automatic_name_ = true;
        name_ = argv[0];
    }

    std::vector<std::string> args;
    args.reserve(static_cast<std::size_t>(argc) - 1U);
    for(auto i = static_cast<std::size_t>(argc) - 1U; i > 0U; --i)
        args.emplace_back(argv[i]);
    parse(std::move(args));
}

CLI11_INLINE void App::parse(std::string commandline, bool program_name_included) {

    if(program_name_included) {
        auto nstr = detail::split_program_name(commandline);
        if((name_.empty()) || (has_automatic_name_)) {
            has_automatic_name_ = true;
            name_ = nstr.first;
        }
        commandline = std::move(nstr.second);
    } else {
        detail::trim(commandline);
    }
    // the next section of code is to deal with quoted arguments after an '=' or ':' for windows like operations
    if(!commandline.empty()) {
        commandline = detail::find_and_modify(commandline, "=", detail::escape_detect);
        if(allow_windows_style_options_)
            commandline = detail::find_and_modify(commandline, ":", detail::escape_detect);
    }

    auto args = detail::split_up(std::move(commandline));
    // remove all empty strings
    args.erase(std::remove(args.begin(), args.end(), std::string{}), args.end());
    std::reverse(args.begin(), args.end());

    parse(std::move(args));
}

CLI11_INLINE void App::parse(std::vector<std::string> &args) {
    // Clear if parsed
    if(parsed_ > 0)
        clear();

    // parsed_ is incremented in commands/subcommands,
    // but placed here to make sure this is cleared when
    // running parse after an error is thrown, even by _validate or _configure.
    parsed_ = 1;
    _validate();
    _configure();
    // set the parent as nullptr as this object should be the top now
    parent_ = nullptr;
    parsed_ = 0;

    _parse(args);
    run_callback();
}

CLI11_INLINE void App::parse(std::vector<std::string> &&args) {
    // Clear if parsed
    if(parsed_ > 0)
        clear();

    // parsed_ is incremented in commands/subcommands,
    // but placed here to make sure this is cleared when
    // running parse after an error is thrown, even by _validate or _configure.
    parsed_ = 1;
    _validate();
    _configure();
    // set the parent as nullptr as this object should be the top now
    parent_ = nullptr;
    parsed_ = 0;

    _parse(std::move(args));
    run_callback();
}

CLI11_INLINE void App::parse_from_stream(std::istream &input) {
    if(parsed_ == 0) {
        _validate();
        _configure();
        // set the parent as nullptr as this object should be the top now
    }

    _parse_stream(input);
    run_callback();
}

CLI11_INLINE int App::exit(const Error &e, std::ostream &out, std::ostream &err) const {

    if(e.get_name() == "RuntimeError")
        return e.get_exit_code();

    if(e.get_name() == "CallForHelp") {
        out << help();
        return e.get_exit_code();
    }

    if(e.get_name() == "CallForAllHelp") {
        out << help("", AppFormatMode::All);
        return e.get_exit_code();
    }

    if(e.get_name() == "CallForVersion") {
        out << e.what() << std::endl;
        return e.get_exit_code();
    }

    if(e.get_exit_code() != static_cast<int>(ExitCodes::Success)) {
        if(failure_message_)
            err << failure_message_(this, e) << std::flush;
    }

    return e.get_exit_code();
}

CLI11_INLINE std::vector<const App *> App::get_subcommands(const std::function<bool(const App *)> &filter) const {
    std::vector<const App *> subcomms(subcommands_.size());
    std::transform(
        std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) { return v.get(); });

    if(filter) {
        subcomms.erase(std::remove_if(std::begin(subcomms),
                                      std::end(subcomms),
                                      [&filter](const App *app) { return !filter(app); }),
                       std::end(subcomms));
    }

    return subcomms;
}

CLI11_INLINE std::vector<App *> App::get_subcommands(const std::function<bool(App *)> &filter) {
    std::vector<App *> subcomms(subcommands_.size());
    std::transform(
        std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) { return v.get(); });

    if(filter) {
        subcomms.erase(
            std::remove_if(std::begin(subcomms), std::end(subcomms), [&filter](App *app) { return !filter(app); }),
            std::end(subcomms));
    }

    return subcomms;
}

CLI11_INLINE bool App::remove_excludes(Option *opt) {
    auto iterator = std::find(std::begin(exclude_options_), std::end(exclude_options_), opt);
    if(iterator == std::end(exclude_options_)) {
        return false;
    }
    exclude_options_.erase(iterator);
    return true;
}

CLI11_INLINE bool App::remove_excludes(App *app) {
    auto iterator = std::find(std::begin(exclude_subcommands_), std::end(exclude_subcommands_), app);
    if(iterator == std::end(exclude_subcommands_)) {
        return false;
    }
    auto *other_app = *iterator;
    exclude_subcommands_.erase(iterator);
    other_app->remove_excludes(this);
    return true;
}

CLI11_INLINE bool App::remove_needs(Option *opt) {
    auto iterator = std::find(std::begin(need_options_), std::end(need_options_), opt);
    if(iterator == std::end(need_options_)) {
        return false;
    }
    need_options_.erase(iterator);
    return true;
}

CLI11_INLINE bool App::remove_needs(App *app) {
    auto iterator = std::find(std::begin(need_subcommands_), std::end(need_subcommands_), app);
    if(iterator == std::end(need_subcommands_)) {
        return false;
    }
    need_subcommands_.erase(iterator);
    return true;
}

CLI11_NODISCARD CLI11_INLINE std::string App::help(std::string prev, AppFormatMode mode) const {
    if(prev.empty())
        prev = get_name();
    else
        prev += " " + get_name();

    // Delegate to subcommand if needed
    auto selected_subcommands = get_subcommands();
    if(!selected_subcommands.empty()) {
        return selected_subcommands.at(0)->help(prev, mode);
    }
    return formatter_->make_help(this, prev, mode);
}

CLI11_NODISCARD CLI11_INLINE std::string App::version() const {
    std::string val;
    if(version_ptr_ != nullptr) {
        auto rv = version_ptr_->results();
        version_ptr_->clear();
        version_ptr_->add_result("true");
        try {
            version_ptr_->run_callback();
        } catch(const CLI::CallForVersion &cfv) {
            val = cfv.what();
        }
        version_ptr_->clear();
        version_ptr_->add_result(rv);
    }
    return val;
}

CLI11_INLINE std::vector<const Option *> App::get_options(const std::function<bool(const Option *)> filter) const {
    std::vector<const Option *> options(options_.size());
    std::transform(
        std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) { return val.get(); });

    if(filter) {
        options.erase(std::remove_if(std::begin(options),
                                     std::end(options),
                                     [&filter](const Option *opt) { return !filter(opt); }),
                      std::end(options));
    }

    return options;
}

CLI11_INLINE std::vector<Option *> App::get_options(const std::function<bool(Option *)> filter) {
    std::vector<Option *> options(options_.size());
    std::transform(
        std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) { return val.get(); });

    if(filter) {
        options.erase(
            std::remove_if(std::begin(options), std::end(options), [&filter](Option *opt) { return !filter(opt); }),
            std::end(options));
    }

    return options;
}

CLI11_INLINE Option *App::get_option_no_throw(std::string option_name) noexcept {
    for(Option_p &opt : options_) {
        if(opt->check_name(option_name)) {
            return opt.get();
        }
    }
    for(auto &subc : subcommands_) {
        // also check down into nameless subcommands
        if(subc->get_name().empty()) {
            auto *opt = subc->get_option_no_throw(option_name);
            if(opt != nullptr) {
                return opt;
            }
        }
    }
    return nullptr;
}

CLI11_NODISCARD CLI11_INLINE const Option *App::get_option_no_throw(std::string option_name) const noexcept {
    for(const Option_p &opt : options_) {
        if(opt->check_name(option_name)) {
            return opt.get();
        }
    }
    for(const auto &subc : subcommands_) {
        // also check down into nameless subcommands
        if(subc->get_name().empty()) {
            auto *opt = subc->get_option_no_throw(option_name);
            if(opt != nullptr) {
                return opt;
            }
        }
    }
    return nullptr;
}

CLI11_NODISCARD CLI11_INLINE std::string App::get_display_name(bool with_aliases) const {
    if(name_.empty()) {
        return std::string("[Option Group: ") + get_group() + "]";
    }
    if(aliases_.empty() || !with_aliases) {
        return name_;
    }
    std::string dispname = name_;
    for(const auto &lalias : aliases_) {
        dispname.push_back(',');
        dispname.push_back(' ');
        dispname.append(lalias);
    }
    return dispname;
}

CLI11_NODISCARD CLI11_INLINE bool App::check_name(std::string name_to_check) const {
    std::string local_name = name_;
    if(ignore_underscore_) {
        local_name = detail::remove_underscore(name_);
        name_to_check = detail::remove_underscore(name_to_check);
    }
    if(ignore_case_) {
        local_name = detail::to_lower(name_);
        name_to_check = detail::to_lower(name_to_check);
    }

    if(local_name == name_to_check) {
        return true;
    }
    for(auto les : aliases_) {  // NOLINT(performance-for-range-copy)
        if(ignore_underscore_) {
            les = detail::remove_underscore(les);
        }
        if(ignore_case_) {
            les = detail::to_lower(les);
        }
        if(les == name_to_check) {
            return true;
        }
    }
    return false;
}

CLI11_NODISCARD CLI11_INLINE std::vector<std::string> App::get_groups() const {
    std::vector<std::string> groups;

    for(const Option_p &opt : options_) {
        // Add group if it is not already in there
        if(std::find(groups.begin(), groups.end(), opt->get_group()) == groups.end()) {
            groups.push_back(opt->get_group());
        }
    }

    return groups;
}

CLI11_NODISCARD CLI11_INLINE std::vector<std::string> App::remaining(bool recurse) const {
    std::vector<std::string> miss_list;
    for(const std::pair<detail::Classifier, std::string> &miss : missing_) {
        miss_list.push_back(std::get<1>(miss));
    }
    // Get from a subcommand that may allow extras
    if(recurse) {
        if(!allow_extras_) {
            for(const auto &sub : subcommands_) {
                if(sub->name_.empty() && !sub->missing_.empty()) {
                    for(const std::pair<detail::Classifier, std::string> &miss : sub->missing_) {
                        miss_list.push_back(std::get<1>(miss));
                    }
                }
            }
        }
        // Recurse into subcommands

        for(const App *sub : parsed_subcommands_) {
            std::vector<std::string> output = sub->remaining(recurse);
            std::copy(std::begin(output), std::end(output), std::back_inserter(miss_list));
        }
    }
    return miss_list;
}

CLI11_NODISCARD CLI11_INLINE std::vector<std::string> App::remaining_for_passthrough(bool recurse) const {
    std::vector<std::string> miss_list = remaining(recurse);
    std::reverse(std::begin(miss_list), std::end(miss_list));
    return miss_list;
}

CLI11_NODISCARD CLI11_INLINE std::size_t App::remaining_size(bool recurse) const {
    auto remaining_options = static_cast<std::size_t>(std::count_if(
        std::begin(missing_), std::end(missing_), [](const std::pair<detail::Classifier, std::string> &val) {
            return val.first != detail::Classifier::POSITIONAL_MARK;
        }));

    if(recurse) {
        for(const App_p &sub : subcommands_) {
            remaining_options += sub->remaining_size(recurse);
        }
    }
    return remaining_options;
}

CLI11_INLINE void App::_validate() const {
    // count the number of positional only args
    auto pcount = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
        return opt->get_items_expected_max() >= detail::expected_max_vector_size && !opt->nonpositional();
    });
    if(pcount > 1) {
        auto pcount_req = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
            return opt->get_items_expected_max() >= detail::expected_max_vector_size && !opt->nonpositional() &&
                   opt->get_required();
        });
        if(pcount - pcount_req > 1) {
            throw InvalidError(name_);
        }
    }

    std::size_t nameless_subs{0};
    for(const App_p &app : subcommands_) {
        app->_validate();
        if(app->get_name().empty())
            ++nameless_subs;
    }

    if(require_option_min_ > 0) {
        if(require_option_max_ > 0) {
            if(require_option_max_ < require_option_min_) {
                throw(InvalidError("Required min options greater than required max options", ExitCodes::InvalidError));
            }
        }
        if(require_option_min_ > (options_.size() + nameless_subs)) {
            throw(
                InvalidError("Required min options greater than number of available options", ExitCodes::InvalidError));
        }
    }
}

CLI11_INLINE void App::_configure() {
    if(default_startup == startup_mode::enabled) {
        disabled_ = false;
    } else if(default_startup == startup_mode::disabled) {
        disabled_ = true;
    }
    for(const App_p &app : subcommands_) {
        if(app->has_automatic_name_) {
            app->name_.clear();
        }
        if(app->name_.empty()) {
            app->fallthrough_ = false;  // make sure fallthrough_ is false to prevent infinite loop
            app->prefix_command_ = false;
        }
        // make sure the parent is set to be this object in preparation for parse
        app->parent_ = this;
        app->_configure();
    }
}

CLI11_INLINE void App::run_callback(bool final_mode, bool suppress_final_callback) {
    pre_callback();
    // in the main app if immediate_callback_ is set it runs the main callback before the used subcommands
    if(!final_mode && parse_complete_callback_) {
        parse_complete_callback_();
    }
    // run the callbacks for the received subcommands
    for(App *subc : get_subcommands()) {
        if(subc->parent_ == this) {
            subc->run_callback(true, suppress_final_callback);
        }
    }
    // now run callbacks for option_groups
    for(auto &subc : subcommands_) {
        if(subc->name_.empty() && subc->count_all() > 0) {
            subc->run_callback(true, suppress_final_callback);
        }
    }

    // finally run the main callback
    if(final_callback_ && (parsed_ > 0) && (!suppress_final_callback)) {
        if(!name_.empty() || count_all() > 0 || parent_ == nullptr) {
            final_callback_();
        }
    }
}

CLI11_NODISCARD CLI11_INLINE bool App::_valid_subcommand(const std::string &current, bool ignore_used) const {
    // Don't match if max has been reached - but still check parents
    if(require_subcommand_max_ != 0 && parsed_subcommands_.size() >= require_subcommand_max_) {
        return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
    }
    auto *com = _find_subcommand(current, true, ignore_used);
    if(com != nullptr) {
        return true;
    }
    // Check parent if exists, else return false
    return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
}

CLI11_NODISCARD CLI11_INLINE detail::Classifier App::_recognize(const std::string &current,
                                                                bool ignore_used_subcommands) const {
    std::string dummy1, dummy2;

    if(current == "--")
        return detail::Classifier::POSITIONAL_MARK;
    if(_valid_subcommand(current, ignore_used_subcommands))
        return detail::Classifier::SUBCOMMAND;
    if(detail::split_long(current, dummy1, dummy2))
        return detail::Classifier::LONG;
    if(detail::split_short(current, dummy1, dummy2)) {
        if(dummy1[0] >= '0' && dummy1[0] <= '9') {
            if(get_option_no_throw(std::string{'-', dummy1[0]}) == nullptr) {
                return detail::Classifier::NONE;
            }
        }
        return detail::Classifier::SHORT;
    }
    if((allow_windows_style_options_) && (detail::split_windows_style(current, dummy1, dummy2)))
        return detail::Classifier::WINDOWS_STYLE;
    if((current == "++") && !name_.empty() && parent_ != nullptr)
        return detail::Classifier::SUBCOMMAND_TERMINATOR;
    return detail::Classifier::NONE;
}

CLI11_INLINE void App::_process_config_file() {
    if(config_ptr_ != nullptr) {
        bool config_required = config_ptr_->get_required();
        auto file_given = config_ptr_->count() > 0;
        auto config_files = config_ptr_->as<std::vector<std::string>>();
        if(config_files.empty() || config_files.front().empty()) {
            if(config_required) {
                throw FileError::Missing("no specified config file");
            }
            return;
        }
        for(auto rit = config_files.rbegin(); rit != config_files.rend(); ++rit) {
            const auto &config_file = *rit;
            auto path_result = detail::check_path(config_file.c_str());
            if(path_result == detail::path_type::file) {
                try {
                    std::vector<ConfigItem> values = config_formatter_->from_file(config_file);
                    _parse_config(values);
                    if(!file_given) {
                        config_ptr_->add_result(config_file);
                    }
                } catch(const FileError &) {
                    if(config_required || file_given)
                        throw;
                }
            } else if(config_required || file_given) {
                throw FileError::Missing(config_file);
            }
        }
    }
}

CLI11_INLINE void App::_process_env() {
    for(const Option_p &opt : options_) {
        if(opt->count() == 0 && !opt->envname_.empty()) {
            char *buffer = nullptr;
            std::string ename_string;

#ifdef _MSC_VER
            // Windows version
            std::size_t sz = 0;
            if(_dupenv_s(&buffer, &sz, opt->envname_.c_str()) == 0 && buffer != nullptr) {
                ename_string = std::string(buffer);
                free(buffer);
            }
#else
            // This also works on Windows, but gives a warning
            buffer = std::getenv(opt->envname_.c_str());
            if(buffer != nullptr)
                ename_string = std::string(buffer);
#endif

            if(!ename_string.empty()) {
                opt->add_result(ename_string);
            }
        }
    }

    for(App_p &sub : subcommands_) {
        if(sub->get_name().empty() || !sub->parse_complete_callback_)
            sub->_process_env();
    }
}

CLI11_INLINE void App::_process_callbacks() {

    for(App_p &sub : subcommands_) {
        // process the priority option_groups first
        if(sub->get_name().empty() && sub->parse_complete_callback_) {
            if(sub->count_all() > 0) {
                sub->_process_callbacks();
                sub->run_callback();
            }
        }
    }

    for(const Option_p &opt : options_) {
        if((*opt) && !opt->get_callback_run()) {
            opt->run_callback();
        }
    }
    for(App_p &sub : subcommands_) {
        if(!sub->parse_complete_callback_) {
            sub->_process_callbacks();
        }
    }
}

CLI11_INLINE void App::_process_help_flags(bool trigger_help, bool trigger_all_help) const {
    const Option *help_ptr = get_help_ptr();
    const Option *help_all_ptr = get_help_all_ptr();

    if(help_ptr != nullptr && help_ptr->count() > 0)
        trigger_help = true;
    if(help_all_ptr != nullptr && help_all_ptr->count() > 0)
        trigger_all_help = true;

    // If there were parsed subcommands, call those. First subcommand wins if there are multiple ones.
    if(!parsed_subcommands_.empty()) {
        for(const App *sub : parsed_subcommands_)
            sub->_process_help_flags(trigger_help, trigger_all_help);

        // Only the final subcommand should call for help. All help wins over help.
    } else if(trigger_all_help) {
        throw CallForAllHelp();
    } else if(trigger_help) {
        throw CallForHelp();
    }
}

CLI11_INLINE void App::_process_requirements() {
    // check excludes
    bool excluded{false};
    std::string excluder;
    for(const auto &opt : exclude_options_) {
        if(opt->count() > 0) {
            excluded = true;
            excluder = opt->get_name();
        }
    }
    for(const auto &subc : exclude_subcommands_) {
        if(subc->count_all() > 0) {
            excluded = true;
            excluder = subc->get_display_name();
        }
    }
    if(excluded) {
        if(count_all() > 0) {
            throw ExcludesError(get_display_name(), excluder);
        }
        // if we are excluded but didn't receive anything, just return
        return;
    }

    // check excludes
    bool missing_needed{false};
    std::string missing_need;
    for(const auto &opt : need_options_) {
        if(opt->count() == 0) {
            missing_needed = true;
            missing_need = opt->get_name();
        }
    }
    for(const auto &subc : need_subcommands_) {
        if(subc->count_all() == 0) {
            missing_needed = true;
            missing_need = subc->get_display_name();
        }
    }
    if(missing_needed) {
        if(count_all() > 0) {
            throw RequiresError(get_display_name(), missing_need);
        }
        // if we missing something but didn't have any options, just return
        return;
    }

    std::size_t used_options = 0;
    for(const Option_p &opt : options_) {

        if(opt->count() != 0) {
            ++used_options;
        }
        // Required but empty
        if(opt->get_required() && opt->count() == 0) {
            throw RequiredError(opt->get_name());
        }
        // Requires
        for(const Option *opt_req : opt->needs_)
            if(opt->count() > 0 && opt_req->count() == 0)
                throw RequiresError(opt->get_name(), opt_req->get_name());
        // Excludes
        for(const Option *opt_ex : opt->excludes_)
            if(opt->count() > 0 && opt_ex->count() != 0)
                throw ExcludesError(opt->get_name(), opt_ex->get_name());
    }
    // check for the required number of subcommands
    if(require_subcommand_min_ > 0) {
        auto selected_subcommands = get_subcommands();
        if(require_subcommand_min_ > selected_subcommands.size())
            throw RequiredError::Subcommand(require_subcommand_min_);
    }

    // Max error cannot occur, the extra subcommand will parse as an ExtrasError or a remaining item.

    // run this loop to check how many unnamed subcommands were actually used since they are considered options
    // from the perspective of an App
    for(App_p &sub : subcommands_) {
        if(sub->disabled_)
            continue;
        if(sub->name_.empty() && sub->count_all() > 0) {
            ++used_options;
        }
    }

    if(require_option_min_ > used_options || (require_option_max_ > 0 && require_option_max_ < used_options)) {
        auto option_list = detail::join(options_, [this](const Option_p &ptr) {
            if(ptr.get() == help_ptr_ || ptr.get() == help_all_ptr_) {
                return std::string{};
            }
            return ptr->get_name(false, true);
        });

        auto subc_list = get_subcommands([](App *app) { return ((app->get_name().empty()) && (!app->disabled_)); });
        if(!subc_list.empty()) {
            option_list += "," + detail::join(subc_list, [](const App *app) { return app->get_display_name(); });
        }
        throw RequiredError::Option(require_option_min_, require_option_max_, used_options, option_list);
    }

    // now process the requirements for subcommands if needed
    for(App_p &sub : subcommands_) {
        if(sub->disabled_)
            continue;
        if(sub->name_.empty() && sub->required_ == false) {
            if(sub->count_all() == 0) {
                if(require_option_min_ > 0 && require_option_min_ <= used_options) {
                    continue;
                    // if we have met the requirement and there is nothing in this option group skip checking
                    // requirements
                }
                if(require_option_max_ > 0 && used_options >= require_option_min_) {
                    continue;
                    // if we have met the requirement and there is nothing in this option group skip checking
                    // requirements
                }
            }
        }
        if(sub->count() > 0 || sub->name_.empty()) {
            sub->_process_requirements();
        }

        if(sub->required_ && sub->count_all() == 0) {
            throw(CLI::RequiredError(sub->get_display_name()));
        }
    }
}

CLI11_INLINE void App::_process() {
    try {
        // the config file might generate a FileError but that should not be processed until later in the process
        // to allow for help, version and other errors to generate first.
        _process_config_file();

        // process env shouldn't throw but no reason to process it if config generated an error
        _process_env();
    } catch(const CLI::FileError &) {
        // callbacks and help_flags can generate exceptions which should take priority
        // over the config file error if one exists.
        _process_callbacks();
        _process_help_flags();
        throw;
    }

    _process_callbacks();
    _process_help_flags();

    _process_requirements();
}

CLI11_INLINE void App::_process_extras() {
    if(!(allow_extras_ || prefix_command_)) {
        std::size_t num_left_over = remaining_size();
        if(num_left_over > 0) {
            throw ExtrasError(name_, remaining(false));
        }
    }

    for(App_p &sub : subcommands_) {
        if(sub->count() > 0)
            sub->_process_extras();
    }
}

CLI11_INLINE void App::_process_extras(std::vector<std::string> &args) {
    if(!(allow_extras_ || prefix_command_)) {
        std::size_t num_left_over = remaining_size();
        if(num_left_over > 0) {
            args = remaining(false);
            throw ExtrasError(name_, args);
        }
    }

    for(App_p &sub : subcommands_) {
        if(sub->count() > 0)
            sub->_process_extras(args);
    }
}

CLI11_INLINE void App::increment_parsed() {
    ++parsed_;
    for(App_p &sub : subcommands_) {
        if(sub->get_name().empty())
            sub->increment_parsed();
    }
}

CLI11_INLINE void App::_parse(std::vector<std::string> &args) {
    increment_parsed();
    _trigger_pre_parse(args.size());
    bool positional_only = false;

    while(!args.empty()) {
        if(!_parse_single(args, positional_only)) {
            break;
        }
    }

    if(parent_ == nullptr) {
        _process();

        // Throw error if any items are left over (depending on settings)
        _process_extras(args);

        // Convert missing (pairs) to extras (string only) ready for processing in another app
        args = remaining_for_passthrough(false);
    } else if(parse_complete_callback_) {
        _process_env();
        _process_callbacks();
        _process_help_flags();
        _process_requirements();
        run_callback(false, true);
    }
}

CLI11_INLINE void App::_parse(std::vector<std::string> &&args) {
    // this can only be called by the top level in which case parent == nullptr by definition
    // operation is simplified
    increment_parsed();
    _trigger_pre_parse(args.size());
    bool positional_only = false;

    while(!args.empty()) {
        _parse_single(args, positional_only);
    }
    _process();

    // Throw error if any items are left over (depending on settings)
    _process_extras();
}

CLI11_INLINE void App::_parse_stream(std::istream &input) {
    auto values = config_formatter_->from_config(input);
    _parse_config(values);
    increment_parsed();
    _trigger_pre_parse(values.size());
    _process();

    // Throw error if any items are left over (depending on settings)
    _process_extras();
}

CLI11_INLINE void App::_parse_config(const std::vector<ConfigItem> &args) {
    for(const ConfigItem &item : args) {
        if(!_parse_single_config(item) && allow_config_extras_ == config_extras_mode::error)
            throw ConfigError::Extras(item.fullname());
    }
}

CLI11_INLINE bool App::_parse_single_config(const ConfigItem &item, std::size_t level) {
    if(level < item.parents.size()) {
        try {
            auto *subcom = get_subcommand(item.parents.at(level));
            auto result = subcom->_parse_single_config(item, level + 1);

            return result;
        } catch(const OptionNotFound &) {
            return false;
        }
    }
    // check for section open
    if(item.name == "++") {
        if(configurable_) {
            increment_parsed();
            _trigger_pre_parse(2);
            if(parent_ != nullptr) {
                parent_->parsed_subcommands_.push_back(this);
            }
        }
        return true;
    }
    // check for section close
    if(item.name == "--") {
        if(configurable_ && parse_complete_callback_) {
            _process_callbacks();
            _process_requirements();
            run_callback();
        }
        return true;
    }
    Option *op = get_option_no_throw("--" + item.name);
    if(op == nullptr) {
        if(item.name.size() == 1) {
            op = get_option_no_throw("-" + item.name);
        }
    }
    if(op == nullptr) {
        op = get_option_no_throw(item.name);
    }
    if(op == nullptr) {
        // If the option was not present
        if(get_allow_config_extras() == config_extras_mode::capture)
            // Should we worry about classifying the extras properly?
            missing_.emplace_back(detail::Classifier::NONE, item.fullname());
        return false;
    }

    if(!op->get_configurable()) {
        if(get_allow_config_extras() == config_extras_mode::ignore_all) {
            return false;
        }
        throw ConfigError::NotConfigurable(item.fullname());
    }

    if(op->empty()) {

        if(op->get_expected_min() == 0) {
            if(item.inputs.size() <= 1) {
                // Flag parsing
                auto res = config_formatter_->to_flag(item);
                res = op->get_flag_value(item.name, res);

                op->add_result(res);
                return true;
            }
            if(static_cast<int>(item.inputs.size()) > op->get_items_expected_max()) {
                if(op->get_items_expected_max() > 1) {
                    throw ArgumentMismatch::AtMost(item.fullname(), op->get_items_expected_max(), item.inputs.size());
                }
                throw ConversionError::TooManyInputsFlag(item.fullname());
            }
        }
        op->add_result(item.inputs);
        op->run_callback();
    }

    return true;
}

CLI11_INLINE bool App::_parse_single(std::vector<std::string> &args, bool &positional_only) {
    bool retval = true;
    detail::Classifier classifier = positional_only ? detail::Classifier::NONE : _recognize(args.back());
    switch(classifier) {
    case detail::Classifier::POSITIONAL_MARK:
        args.pop_back();
        positional_only = true;
        if((!_has_remaining_positionals()) && (parent_ != nullptr)) {
            retval = false;
        } else {
            _move_to_missing(classifier, "--");
        }
        break;
    case detail::Classifier::SUBCOMMAND_TERMINATOR:
        // treat this like a positional mark if in the parent app
        args.pop_back();
        retval = false;
        break;
    case detail::Classifier::SUBCOMMAND:
        retval = _parse_subcommand(args);
        break;
    case detail::Classifier::LONG:
    case detail::Classifier::SHORT:
    case detail::Classifier::WINDOWS_STYLE:
        // If already parsed a subcommand, don't accept options_
        _parse_arg(args, classifier);
        break;
    case detail::Classifier::NONE:
        // Probably a positional or something for a parent (sub)command
        retval = _parse_positional(args, false);
        if(retval && positionals_at_end_) {
            positional_only = true;
        }
        break;
        // LCOV_EXCL_START
    default:
        throw HorribleError("unrecognized classifier (you should not see this!)");
        // LCOV_EXCL_STOP
    }
    return retval;
}

CLI11_NODISCARD CLI11_INLINE std::size_t App::_count_remaining_positionals(bool required_only) const {
    std::size_t retval = 0;
    for(const Option_p &opt : options_) {
        if(opt->get_positional() && (!required_only || opt->get_required())) {
            if(opt->get_items_expected_min() > 0 && static_cast<int>(opt->count()) < opt->get_items_expected_min()) {
                retval += static_cast<std::size_t>(opt->get_items_expected_min()) - opt->count();
            }
        }
    }
    return retval;
}

CLI11_NODISCARD CLI11_INLINE bool App::_has_remaining_positionals() const {
    for(const Option_p &opt : options_) {
        if(opt->get_positional() && ((static_cast<int>(opt->count()) < opt->get_items_expected_min()))) {
            return true;
        }
    }

    return false;
}

CLI11_INLINE bool App::_parse_positional(std::vector<std::string> &args, bool haltOnSubcommand) {

    const std::string &positional = args.back();

    if(positionals_at_end_) {
        // deal with the case of required arguments at the end which should take precedence over other arguments
        auto arg_rem = args.size();
        auto remreq = _count_remaining_positionals(true);
        if(arg_rem <= remreq) {
            for(const Option_p &opt : options_) {
                if(opt->get_positional() && opt->required_) {
                    if(static_cast<int>(opt->count()) < opt->get_items_expected_min()) {
                        if(validate_positionals_) {
                            std::string pos = positional;
                            pos = opt->_validate(pos, 0);
                            if(!pos.empty()) {
                                continue;
                            }
                        }

                        parse_order_.push_back(opt.get());
                        if(opt->get_inject_separator()) {
                            if(!opt->results().empty() && !opt->results().back().empty()) {
                                opt->add_result(std::string{});
                            }
                        }
                        if(opt->get_trigger_on_parse() &&
                           opt->current_option_state_ == Option::option_state::callback_run) {
                            opt->clear();
                        }
                        opt->add_result(positional);
                        if(opt->get_trigger_on_parse()) {
                            opt->run_callback();
                        }
                        args.pop_back();
                        return true;
                    }
                }
            }
        }
    }
    for(const Option_p &opt : options_) {
        // Eat options, one by one, until done
        if(opt->get_positional() &&
           (static_cast<int>(opt->count()) < opt->get_items_expected_min() || opt->get_allow_extra_args())) {
            if(validate_positionals_) {
                std::string pos = positional;
                pos = opt->_validate(pos, 0);
                if(!pos.empty()) {
                    continue;
                }
            }
            if(opt->get_inject_separator()) {
                if(!opt->results().empty() && !opt->results().back().empty()) {
                    opt->add_result(std::string{});
                }
            }
            if(opt->get_trigger_on_parse() && opt->current_option_state_ == Option::option_state::callback_run) {
                opt->clear();
            }
            opt->add_result(positional);
            if(opt->get_trigger_on_parse()) {
                opt->run_callback();
            }
            parse_order_.push_back(opt.get());
            args.pop_back();
            return true;
        }
    }

    for(auto &subc : subcommands_) {
        if((subc->name_.empty()) && (!subc->disabled_)) {
            if(subc->_parse_positional(args, false)) {
                if(!subc->pre_parse_called_) {
                    subc->_trigger_pre_parse(args.size());
                }
                return true;
            }
        }
    }
    // let the parent deal with it if possible
    if(parent_ != nullptr && fallthrough_)
        return _get_fallthrough_parent()->_parse_positional(args, static_cast<bool>(parse_complete_callback_));

    auto *com = _find_subcommand(args.back(), true, false);
    if(com != nullptr && (require_subcommand_max_ == 0 || require_subcommand_max_ > parsed_subcommands_.size())) {
        if(haltOnSubcommand) {
            return false;
        }
        args.pop_back();
        com->_parse(args);
        return true;
    }
    auto *parent_app = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
    com = parent_app->_find_subcommand(args.back(), true, false);
    if(com != nullptr && (com->parent_->require_subcommand_max_ == 0 ||
                          com->parent_->require_subcommand_max_ > com->parent_->parsed_subcommands_.size())) {
        return false;
    }

    if(positionals_at_end_) {
        throw CLI::ExtrasError(name_, args);
    }
    if(parent_ != nullptr && name_.empty()) {
        return false;
    }
    _move_to_missing(detail::Classifier::NONE, positional);
    args.pop_back();
    if(prefix_command_) {
        while(!args.empty()) {
            _move_to_missing(detail::Classifier::NONE, args.back());
            args.pop_back();
        }
    }

    return true;
}

CLI11_NODISCARD CLI11_INLINE App *
App::_find_subcommand(const std::string &subc_name, bool ignore_disabled, bool ignore_used) const noexcept {
    for(const App_p &com : subcommands_) {
        if(com->disabled_ && ignore_disabled)
            continue;
        if(com->get_name().empty()) {
            auto *subc = com->_find_subcommand(subc_name, ignore_disabled, ignore_used);
            if(subc != nullptr) {
                return subc;
            }
        }
        if(com->check_name(subc_name)) {
            if((!*com) || !ignore_used)
                return com.get();
        }
    }
    return nullptr;
}

CLI11_INLINE bool App::_parse_subcommand(std::vector<std::string> &args) {
    if(_count_remaining_positionals(/* required */ true) > 0) {
        _parse_positional(args, false);
        return true;
    }
    auto *com = _find_subcommand(args.back(), true, true);
    if(com != nullptr) {
        args.pop_back();
        if(!com->silent_) {
            parsed_subcommands_.push_back(com);
        }
        com->_parse(args);
        auto *parent_app = com->parent_;
        while(parent_app != this) {
            parent_app->_trigger_pre_parse(args.size());
            if(!com->silent_) {
                parent_app->parsed_subcommands_.push_back(com);
            }
            parent_app = parent_app->parent_;
        }
        return true;
    }

    if(parent_ == nullptr)
        throw HorribleError("Subcommand " + args.back() + " missing");
    return false;
}

CLI11_INLINE bool App::_parse_arg(std::vector<std::string> &args, detail::Classifier current_type) {

    std::string current = args.back();

    std::string arg_name;
    std::string value;
    std::string rest;

    switch(current_type) {
    case detail::Classifier::LONG:
        if(!detail::split_long(current, arg_name, value))
            throw HorribleError("Long parsed but missing (you should not see this):" + args.back());
        break;
    case detail::Classifier::SHORT:
        if(!detail::split_short(current, arg_name, rest))
            throw HorribleError("Short parsed but missing! You should not see this");
        break;
    case detail::Classifier::WINDOWS_STYLE:
        if(!detail::split_windows_style(current, arg_name, value))
            throw HorribleError("windows option parsed but missing! You should not see this");
        break;
    case detail::Classifier::SUBCOMMAND:
    case detail::Classifier::SUBCOMMAND_TERMINATOR:
    case detail::Classifier::POSITIONAL_MARK:
    case detail::Classifier::NONE:
    default:
        throw HorribleError("parsing got called with invalid option! You should not see this");
    }

    auto op_ptr = std::find_if(std::begin(options_), std::end(options_), [arg_name, current_type](const Option_p &opt) {
        if(current_type == detail::Classifier::LONG)
            return opt->check_lname(arg_name);
        if(current_type == detail::Classifier::SHORT)
            return opt->check_sname(arg_name);
        // this will only get called for detail::Classifier::WINDOWS_STYLE
        return opt->check_lname(arg_name) || opt->check_sname(arg_name);
    });

    // Option not found
    if(op_ptr == std::end(options_)) {
        for(auto &subc : subcommands_) {
            if(subc->name_.empty() && !subc->disabled_) {
                if(subc->_parse_arg(args, current_type)) {
                    if(!subc->pre_parse_called_) {
                        subc->_trigger_pre_parse(args.size());
                    }
                    return true;
                }
            }
        }

        // don't capture missing if this is a nameless subcommand and nameless subcommands can't fallthrough
        if(parent_ != nullptr && name_.empty()) {
            return false;
        }

        // If a subcommand, try the main command
        if(parent_ != nullptr && fallthrough_)
            return _get_fallthrough_parent()->_parse_arg(args, current_type);

        // Otherwise, add to missing
        args.pop_back();
        _move_to_missing(current_type, current);
        return true;
    }

    args.pop_back();

    // Get a reference to the pointer to make syntax bearable
    Option_p &op = *op_ptr;
    if(op->get_inject_separator()) {
        if(!op->results().empty() && !op->results().back().empty()) {
            op->add_result(std::string{});
        }
    }
    if(op->get_trigger_on_parse() && op->current_option_state_ == Option::option_state::callback_run) {
        op->clear();
    }
    int min_num = (std::min)(op->get_type_size_min(), op->get_items_expected_min());
    int max_num = op->get_items_expected_max();
    // check container like options to limit the argument size to a single type if the allow_extra_flags argument is
    // set. 16 is somewhat arbitrary (needs to be at least 4)
    if(max_num >= detail::expected_max_vector_size / 16 && !op->get_allow_extra_args()) {
        auto tmax = op->get_type_size_max();
        max_num = detail::checked_multiply(tmax, op->get_expected_min()) ? tmax : detail::expected_max_vector_size;
    }
    // Make sure we always eat the minimum for unlimited vectors
    int collected = 0;     // total number of arguments collected
    int result_count = 0;  // local variable for number of results in a single arg string
    // deal with purely flag like things
    if(max_num == 0) {
        auto res = op->get_flag_value(arg_name, value);
        op->add_result(res);
        parse_order_.push_back(op.get());
    } else if(!value.empty()) {  // --this=value
        op->add_result(value, result_count);
        parse_order_.push_back(op.get());
        collected += result_count;
        // -Trest
    } else if(!rest.empty()) {
        op->add_result(rest, result_count);
        parse_order_.push_back(op.get());
        rest = "";
        collected += result_count;
    }

    // gather the minimum number of arguments
    while(min_num > collected && !args.empty()) {
        std::string current_ = args.back();
        args.pop_back();
        op->add_result(current_, result_count);
        parse_order_.push_back(op.get());
        collected += result_count;
    }

    if(min_num > collected) {  // if we have run out of arguments and the minimum was not met
        throw ArgumentMismatch::TypedAtLeast(op->get_name(), min_num, op->get_type_name());
    }

    // now check for optional arguments
    if(max_num > collected || op->get_allow_extra_args()) {  // we allow optional arguments
        auto remreqpos = _count_remaining_positionals(true);
        // we have met the minimum now optionally check up to the maximum
        while((collected < max_num || op->get_allow_extra_args()) && !args.empty() &&
              _recognize(args.back(), false) == detail::Classifier::NONE) {
            // If any required positionals remain, don't keep eating
            if(remreqpos >= args.size()) {
                break;
            }
            if(validate_optional_arguments_) {
                std::string arg = args.back();
                arg = op->_validate(arg, 0);
                if(!arg.empty()) {
                    break;
                }
            }
            op->add_result(args.back(), result_count);
            parse_order_.push_back(op.get());
            args.pop_back();
            collected += result_count;
        }

        // Allow -- to end an unlimited list and "eat" it
        if(!args.empty() && _recognize(args.back()) == detail::Classifier::POSITIONAL_MARK)
            args.pop_back();
        // optional flag that didn't receive anything now get the default value
        if(min_num == 0 && max_num > 0 && collected == 0) {
            auto res = op->get_flag_value(arg_name, std::string{});
            op->add_result(res);
            parse_order_.push_back(op.get());
        }
    }
    // if we only partially completed a type then add an empty string if allowed for later processing
    if(min_num > 0 && (collected % op->get_type_size_max()) != 0) {
        if(op->get_type_size_max() != op->get_type_size_min()) {
            op->add_result(std::string{});
        } else {
            throw ArgumentMismatch::PartialType(op->get_name(), op->get_type_size_min(), op->get_type_name());
        }
    }
    if(op->get_trigger_on_parse()) {
        op->run_callback();
    }
    if(!rest.empty()) {
        rest = "-" + rest;
        args.push_back(rest);
    }
    return true;
}

CLI11_INLINE void App::_trigger_pre_parse(std::size_t remaining_args) {
    if(!pre_parse_called_) {
        pre_parse_called_ = true;
        if(pre_parse_callback_) {
            pre_parse_callback_(remaining_args);
        }
    } else if(immediate_callback_) {
        if(!name_.empty()) {
            auto pcnt = parsed_;
            auto extras = std::move(missing_);
            clear();
            parsed_ = pcnt;
            pre_parse_called_ = true;
            missing_ = std::move(extras);
        }
    }
}

CLI11_INLINE App *App::_get_fallthrough_parent() {
    if(parent_ == nullptr) {
        throw(HorribleError("No Valid parent"));
    }
    auto *fallthrough_parent = parent_;
    while((fallthrough_parent->parent_ != nullptr) && (fallthrough_parent->get_name().empty())) {
        fallthrough_parent = fallthrough_parent->parent_;
    }
    return fallthrough_parent;
}

CLI11_NODISCARD CLI11_INLINE const std::string &App::_compare_subcommand_names(const App &subcom,
                                                                               const App &base) const {
    static const std::string estring;
    if(subcom.disabled_) {
        return estring;
    }
    for(const auto &subc : base.subcommands_) {
        if(subc.get() != &subcom) {
            if(subc->disabled_) {
                continue;
            }
            if(!subcom.get_name().empty()) {
                if(subc->check_name(subcom.get_name())) {
                    return subcom.get_name();
                }
            }
            if(!subc->get_name().empty()) {
                if(subcom.check_name(subc->get_name())) {
                    return subc->get_name();
                }
            }
            for(const auto &les : subcom.aliases_) {
                if(subc->check_name(les)) {
                    return les;
                }
            }
            // this loop is needed in case of ignore_underscore or ignore_case on one but not the other
            for(const auto &les : subc->aliases_) {
                if(subcom.check_name(les)) {
                    return les;
                }
            }
            // if the subcommand is an option group we need to check deeper
            if(subc->get_name().empty()) {
                const auto &cmpres = _compare_subcommand_names(subcom, *subc);
                if(!cmpres.empty()) {
                    return cmpres;
                }
            }
            // if the test subcommand is an option group we need to check deeper
            if(subcom.get_name().empty()) {
                const auto &cmpres = _compare_subcommand_names(*subc, subcom);
                if(!cmpres.empty()) {
                    return cmpres;
                }
            }
        }
    }
    return estring;
}

CLI11_INLINE void App::_move_to_missing(detail::Classifier val_type, const std::string &val) {
    if(allow_extras_ || subcommands_.empty()) {
        missing_.emplace_back(val_type, val);
        return;
    }
    // allow extra arguments to be places in an option group if it is allowed there
    for(auto &subc : subcommands_) {
        if(subc->name_.empty() && subc->allow_extras_) {
            subc->missing_.emplace_back(val_type, val);
            return;
        }
    }
    // if we haven't found any place to put them yet put them in missing
    missing_.emplace_back(val_type, val);
}

CLI11_INLINE void App::_move_option(Option *opt, App *app) {
    if(opt == nullptr) {
        throw OptionNotFound("the option is NULL");
    }
    // verify that the give app is actually a subcommand
    bool found = false;
    for(auto &subc : subcommands_) {
        if(app == subc.get()) {
            found = true;
        }
    }
    if(!found) {
        throw OptionNotFound("The Given app is not a subcommand");
    }

    if((help_ptr_ == opt) || (help_all_ptr_ == opt))
        throw OptionAlreadyAdded("cannot move help options");

    if(config_ptr_ == opt)
        throw OptionAlreadyAdded("cannot move config file options");

    auto iterator =
        std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
    if(iterator != std::end(options_)) {
        const auto &opt_p = *iterator;
        if(std::find_if(std::begin(app->options_), std::end(app->options_), [&opt_p](const Option_p &v) {
               return (*v == *opt_p);
           }) == std::end(app->options_)) {
            // only erase after the insertion was successful
            app->options_.push_back(std::move(*iterator));
            options_.erase(iterator);
        } else {
            throw OptionAlreadyAdded("option was not located: " + opt->get_name());
        }
    } else {
        throw OptionNotFound("could not locate the given Option");
    }
}

CLI11_INLINE void TriggerOn(App *trigger_app, App *app_to_enable) {
    app_to_enable->enabled_by_default(false);
    app_to_enable->disabled_by_default();
    trigger_app->preparse_callback([app_to_enable](std::size_t) { app_to_enable->disabled(false); });
}

CLI11_INLINE void TriggerOn(App *trigger_app, std::vector<App *> apps_to_enable) {
    for(auto &app : apps_to_enable) {
        app->enabled_by_default(false);
        app->disabled_by_default();
    }

    trigger_app->preparse_callback([apps_to_enable](std::size_t) {
        for(const auto &app : apps_to_enable) {
            app->disabled(false);
        }
    });
}

CLI11_INLINE void TriggerOff(App *trigger_app, App *app_to_enable) {
    app_to_enable->disabled_by_default(false);
    app_to_enable->enabled_by_default();
    trigger_app->preparse_callback([app_to_enable](std::size_t) { app_to_enable->disabled(); });
}

CLI11_INLINE void TriggerOff(App *trigger_app, std::vector<App *> apps_to_enable) {
    for(auto &app : apps_to_enable) {
        app->disabled_by_default(false);
        app->enabled_by_default();
    }

    trigger_app->preparse_callback([apps_to_enable](std::size_t) {
        for(const auto &app : apps_to_enable) {
            app->disabled();
        }
    });
}

CLI11_INLINE void deprecate_option(Option *opt, const std::string &replacement) {
    Validator deprecate_warning{[opt, replacement](std::string &) {
                                    std::cout << opt->get_name() << " is deprecated please use '" << replacement
                                              << "' instead\n";
                                    return std::string();
                                },
                                "DEPRECATED"};
    deprecate_warning.application_index(0);
    opt->check(deprecate_warning);
    if(!replacement.empty()) {
        opt->description(opt->get_description() + " DEPRECATED: please use '" + replacement + "' instead");
    }
}

CLI11_INLINE void retire_option(App *app, Option *opt) {
    App temp;
    auto *option_copy = temp.add_option(opt->get_name(false, true))
                            ->type_size(opt->get_type_size_min(), opt->get_type_size_max())
                            ->expected(opt->get_expected_min(), opt->get_expected_max())
                            ->allow_extra_args(opt->get_allow_extra_args());

    app->remove_option(opt);
    auto *opt2 = app->add_option(option_copy->get_name(false, true), "option has been retired and has no effect")
                     ->type_name("RETIRED")
                     ->default_str("RETIRED")
                     ->type_size(option_copy->get_type_size_min(), option_copy->get_type_size_max())
                     ->expected(option_copy->get_expected_min(), option_copy->get_expected_max())
                     ->allow_extra_args(option_copy->get_allow_extra_args());

    Validator retired_warning{[opt2](std::string &) {
                                  std::cout << "WARNING " << opt2->get_name() << " is retired and has no effect\n";
                                  return std::string();
                              },
                              ""};
    retired_warning.application_index(0);
    opt2->check(retired_warning);
}

CLI11_INLINE void retire_option(App &app, Option *opt) { retire_option(&app, opt); }

CLI11_INLINE void retire_option(App *app, const std::string &option_name) {

    auto *opt = app->get_option_no_throw(option_name);
    if(opt != nullptr) {
        retire_option(app, opt);
        return;
    }
    auto *opt2 = app->add_option(option_name, "option has been retired and has no effect")
                     ->type_name("RETIRED")
                     ->expected(0, 1)
                     ->default_str("RETIRED");
    Validator retired_warning{[opt2](std::string &) {
                                  std::cout << "WARNING " << opt2->get_name() << " is retired and has no effect\n";
                                  return std::string();
                              },
                              ""};
    retired_warning.application_index(0);
    opt2->check(retired_warning);
}

CLI11_INLINE void retire_option(App &app, const std::string &option_name) { retire_option(&app, option_name); }

namespace FailureMessage {

CLI11_INLINE std::string simple(const App *app, const Error &e) {
    std::string header = std::string(e.what()) + "\n";
    std::vector<std::string> names;

    // Collect names
    if(app->get_help_ptr() != nullptr)
        names.push_back(app->get_help_ptr()->get_name());

    if(app->get_help_all_ptr() != nullptr)
        names.push_back(app->get_help_all_ptr()->get_name());

    // If any names found, suggest those
    if(!names.empty())
        header += "Run with " + detail::join(names, " or ") + " for more information.\n";

    return header;
}

CLI11_INLINE std::string help(const App *app, const Error &e) {
    std::string header = std::string("ERROR: ") + e.get_name() + ": " + e.what() + "\n";
    header += app->help();
    return header;
}

}  // namespace FailureMessage




namespace detail {

std::string convert_arg_for_ini(const std::string &arg, char stringQuote = '"', char characterQuote = '\'');

std::string ini_join(const std::vector<std::string> &args,
                     char sepChar = ',',
                     char arrayStart = '[',
                     char arrayEnd = ']',
                     char stringQuote = '"',
                     char characterQuote = '\'');

std::vector<std::string> generate_parents(const std::string &section, std::string &name, char parentSeparator);

void checkParentSegments(std::vector<ConfigItem> &output, const std::string &currentSection, char parentSeparator);
}  // namespace detail




namespace detail {

CLI11_INLINE std::string convert_arg_for_ini(const std::string &arg, char stringQuote, char characterQuote) {
    if(arg.empty()) {
        return std::string(2, stringQuote);
    }
    // some specifically supported strings
    if(arg == "true" || arg == "false" || arg == "nan" || arg == "inf") {
        return arg;
    }
    // floating point conversion can convert some hex codes, but don't try that here
    if(arg.compare(0, 2, "0x") != 0 && arg.compare(0, 2, "0X") != 0) {
        double val = 0.0;
        if(detail::lexical_cast(arg, val)) {
            return arg;
        }
    }
    // just quote a single non numeric character
    if(arg.size() == 1) {
        return std::string(1, characterQuote) + arg + characterQuote;
    }
    // handle hex, binary or octal arguments
    if(arg.front() == '0') {
        if(arg[1] == 'x') {
            if(std::all_of(arg.begin() + 2, arg.end(), [](char x) {
                   return (x >= '0' && x <= '9') || (x >= 'A' && x <= 'F') || (x >= 'a' && x <= 'f');
               })) {
                return arg;
            }
        } else if(arg[1] == 'o') {
            if(std::all_of(arg.begin() + 2, arg.end(), [](char x) { return (x >= '0' && x <= '7'); })) {
                return arg;
            }
        } else if(arg[1] == 'b') {
            if(std::all_of(arg.begin() + 2, arg.end(), [](char x) { return (x == '0' || x == '1'); })) {
                return arg;
            }
        }
    }
    if(arg.find_first_of(stringQuote) == std::string::npos) {
        return std::string(1, stringQuote) + arg + stringQuote;
    }
    return characterQuote + arg + characterQuote;
}

CLI11_INLINE std::string ini_join(const std::vector<std::string> &args,
                                  char sepChar,
                                  char arrayStart,
                                  char arrayEnd,
                                  char stringQuote,
                                  char characterQuote) {
    std::string joined;
    if(args.size() > 1 && arrayStart != '\0') {
        joined.push_back(arrayStart);
    }
    std::size_t start = 0;
    for(const auto &arg : args) {
        if(start++ > 0) {
            joined.push_back(sepChar);
            if(!std::isspace<char>(sepChar, std::locale())) {
                joined.push_back(' ');
            }
        }
        joined.append(convert_arg_for_ini(arg, stringQuote, characterQuote));
    }
    if(args.size() > 1 && arrayEnd != '\0') {
        joined.push_back(arrayEnd);
    }
    return joined;
}

CLI11_INLINE std::vector<std::string>
generate_parents(const std::string &section, std::string &name, char parentSeparator) {
    std::vector<std::string> parents;
    if(detail::to_lower(section) != "default") {
        if(section.find(parentSeparator) != std::string::npos) {
            parents = detail::split(section, parentSeparator);
        } else {
            parents = {section};
        }
    }
    if(name.find(parentSeparator) != std::string::npos) {
        std::vector<std::string> plist = detail::split(name, parentSeparator);
        name = plist.back();
        detail::remove_quotes(name);
        plist.pop_back();
        parents.insert(parents.end(), plist.begin(), plist.end());
    }

    // clean up quotes on the parents
    for(auto &parent : parents) {
        detail::remove_quotes(parent);
    }
    return parents;
}

CLI11_INLINE void
checkParentSegments(std::vector<ConfigItem> &output, const std::string &currentSection, char parentSeparator) {

    std::string estring;
    auto parents = detail::generate_parents(currentSection, estring, parentSeparator);
    if(!output.empty() && output.back().name == "--") {
        std::size_t msize = (parents.size() > 1U) ? parents.size() : 2;
        while(output.back().parents.size() >= msize) {
            output.push_back(output.back());
            output.back().parents.pop_back();
        }

        if(parents.size() > 1) {
            std::size_t common = 0;
            std::size_t mpair = (std::min)(output.back().parents.size(), parents.size() - 1);
            for(std::size_t ii = 0; ii < mpair; ++ii) {
                if(output.back().parents[ii] != parents[ii]) {
                    break;
                }
                ++common;
            }
            if(common == mpair) {
                output.pop_back();
            } else {
                while(output.back().parents.size() > common + 1) {
                    output.push_back(output.back());
                    output.back().parents.pop_back();
                }
            }
            for(std::size_t ii = common; ii < parents.size() - 1; ++ii) {
                output.emplace_back();
                output.back().parents.assign(parents.begin(), parents.begin() + static_cast<std::ptrdiff_t>(ii) + 1);
                output.back().name = "++";
            }
        }
    } else if(parents.size() > 1) {
        for(std::size_t ii = 0; ii < parents.size() - 1; ++ii) {
            output.emplace_back();
            output.back().parents.assign(parents.begin(), parents.begin() + static_cast<std::ptrdiff_t>(ii) + 1);
            output.back().name = "++";
        }
    }

    // insert a section end which is just an empty items_buffer
    output.emplace_back();
    output.back().parents = std::move(parents);
    output.back().name = "++";
}
}  // namespace detail

inline std::vector<ConfigItem> ConfigBase::from_config(std::istream &input) const {
    std::string line;
    std::string currentSection = "default";
    std::string previousSection = "default";
    std::vector<ConfigItem> output;
    bool isDefaultArray = (arrayStart == '[' && arrayEnd == ']' && arraySeparator == ',');
    bool isINIArray = (arrayStart == '\0' || arrayStart == ' ') && arrayStart == arrayEnd;
    bool inSection{false};
    char aStart = (isINIArray) ? '[' : arrayStart;
    char aEnd = (isINIArray) ? ']' : arrayEnd;
    char aSep = (isINIArray && arraySeparator == ' ') ? ',' : arraySeparator;
    int currentSectionIndex{0};
    while(getline(input, line)) {
        std::vector<std::string> items_buffer;
        std::string name;

        detail::trim(line);
        std::size_t len = line.length();
        // lines have to be at least 3 characters to have any meaning to CLI just skip the rest
        if(len < 3) {
            continue;
        }
        if(line.front() == '[' && line.back() == ']') {
            if(currentSection != "default") {
                // insert a section end which is just an empty items_buffer
                output.emplace_back();
                output.back().parents = detail::generate_parents(currentSection, name, parentSeparatorChar);
                output.back().name = "--";
            }
            currentSection = line.substr(1, len - 2);
            // deal with double brackets for TOML
            if(currentSection.size() > 1 && currentSection.front() == '[' && currentSection.back() == ']') {
                currentSection = currentSection.substr(1, currentSection.size() - 2);
            }
            if(detail::to_lower(currentSection) == "default") {
                currentSection = "default";
            } else {
                detail::checkParentSegments(output, currentSection, parentSeparatorChar);
            }
            inSection = false;
            if(currentSection == previousSection) {
                ++currentSectionIndex;
            } else {
                currentSectionIndex = 0;
                previousSection = currentSection;
            }
            continue;
        }

        // comment lines
        if(line.front() == ';' || line.front() == '#' || line.front() == commentChar) {
            continue;
        }

        // Find = in string, split and recombine
        auto pos = line.find(valueDelimiter);
        if(pos != std::string::npos) {
            name = detail::trim_copy(line.substr(0, pos));
            std::string item = detail::trim_copy(line.substr(pos + 1));
            auto cloc = item.find(commentChar);
            if(cloc != std::string::npos) {
                item.erase(cloc, std::string::npos);  // NOLINT(readability-suspicious-call-argument)
                detail::trim(item);
            }
            if(item.size() > 1 && item.front() == aStart) {
                for(std::string multiline; item.back() != aEnd && std::getline(input, multiline);) {
                    detail::trim(multiline);
                    item += multiline;
                }
                items_buffer = detail::split_up(item.substr(1, item.length() - 2), aSep);
            } else if((isDefaultArray || isINIArray) && item.find_first_of(aSep) != std::string::npos) {
                items_buffer = detail::split_up(item, aSep);
            } else if((isDefaultArray || isINIArray) && item.find_first_of(' ') != std::string::npos) {
                items_buffer = detail::split_up(item);
            } else {
                items_buffer = {item};
            }
        } else {
            name = detail::trim_copy(line);
            auto cloc = name.find(commentChar);
            if(cloc != std::string::npos) {
                name.erase(cloc, std::string::npos);  // NOLINT(readability-suspicious-call-argument)
                detail::trim(name);
            }

            items_buffer = {"true"};
        }
        if(name.find(parentSeparatorChar) == std::string::npos) {
            detail::remove_quotes(name);
        }
        // clean up quotes on the items
        for(auto &it : items_buffer) {
            detail::remove_quotes(it);
        }

        std::vector<std::string> parents = detail::generate_parents(currentSection, name, parentSeparatorChar);
        if(parents.size() > maximumLayers) {
            continue;
        }
        if(!configSection.empty() && !inSection) {
            if(parents.empty() || parents.front() != configSection) {
                continue;
            }
            if(configIndex >= 0 && currentSectionIndex != configIndex) {
                continue;
            }
            parents.erase(parents.begin());
            inSection = true;
        }
        if(!output.empty() && name == output.back().name && parents == output.back().parents) {
            output.back().inputs.insert(output.back().inputs.end(), items_buffer.begin(), items_buffer.end());
        } else {
            output.emplace_back();
            output.back().parents = std::move(parents);
            output.back().name = std::move(name);
            output.back().inputs = std::move(items_buffer);
        }
    }
    if(currentSection != "default") {
        // insert a section end which is just an empty items_buffer
        std::string ename;
        output.emplace_back();
        output.back().parents = detail::generate_parents(currentSection, ename, parentSeparatorChar);
        output.back().name = "--";
        while(output.back().parents.size() > 1) {
            output.push_back(output.back());
            output.back().parents.pop_back();
        }
    }
    return output;
}

CLI11_INLINE std::string
ConfigBase::to_config(const App *app, bool default_also, bool write_description, std::string prefix) const {
    std::stringstream out;
    std::string commentLead;
    commentLead.push_back(commentChar);
    commentLead.push_back(' ');

    std::vector<std::string> groups = app->get_groups();
    bool defaultUsed = false;
    groups.insert(groups.begin(), std::string("Options"));
    if(write_description && (app->get_configurable() || app->get_parent() == nullptr || app->get_name().empty())) {
        out << commentLead << detail::fix_newlines(commentLead, app->get_description()) << '\n';
    }
    for(auto &group : groups) {
        if(group == "Options" || group.empty()) {
            if(defaultUsed) {
                continue;
            }
            defaultUsed = true;
        }
        if(write_description && group != "Options" && !group.empty()) {
            out << '\n' << commentLead << group << " Options\n";
        }
        for(const Option *opt : app->get_options({})) {

            // Only process options that are configurable
            if(opt->get_configurable()) {
                if(opt->get_group() != group) {
                    if(!(group == "Options" && opt->get_group().empty())) {
                        continue;
                    }
                }
                std::string name = prefix + opt->get_single_name();
                std::string value = detail::ini_join(
                    opt->reduced_results(), arraySeparator, arrayStart, arrayEnd, stringQuote, characterQuote);

                if(value.empty() && default_also) {
                    if(!opt->get_default_str().empty()) {
                        value = detail::convert_arg_for_ini(opt->get_default_str(), stringQuote, characterQuote);
                    } else if(opt->get_expected_min() == 0) {
                        value = "false";
                    } else if(opt->get_run_callback_for_default()) {
                        value = "\"\"";  // empty string default value
                    }
                }

                if(!value.empty()) {
                    if(!opt->get_fnames().empty()) {
                        value = opt->get_flag_value(name, value);
                    }
                    if(write_description && opt->has_description()) {
                        out << '\n';
                        out << commentLead << detail::fix_newlines(commentLead, opt->get_description()) << '\n';
                    }
                    out << name << valueDelimiter << value << '\n';
                }
            }
        }
    }
    auto subcommands = app->get_subcommands({});
    for(const App *subcom : subcommands) {
        if(subcom->get_name().empty()) {
            if(write_description && !subcom->get_group().empty()) {
                out << '\n' << commentLead << subcom->get_group() << " Options\n";
            }
            out << to_config(subcom, default_also, write_description, prefix);
        }
    }

    for(const App *subcom : subcommands) {
        if(!subcom->get_name().empty()) {
            if(subcom->get_configurable() && app->got_subcommand(subcom)) {
                if(!prefix.empty() || app->get_parent() == nullptr) {
                    out << '[' << prefix << subcom->get_name() << "]\n";
                } else {
                    std::string subname = app->get_name() + parentSeparatorChar + subcom->get_name();
                    const auto *p = app->get_parent();
                    while(p->get_parent() != nullptr) {
                        subname = p->get_name() + parentSeparatorChar + subname;
                        p = p->get_parent();
                    }
                    out << '[' << subname << "]\n";
                }
                out << to_config(subcom, default_also, write_description, "");
            } else {
                out << to_config(
                    subcom, default_also, write_description, prefix + subcom->get_name() + parentSeparatorChar);
            }
        }
    }

    return out.str();
}






CLI11_INLINE std::string
Formatter::make_group(std::string group, bool is_positional, std::vector<const Option *> opts) const {
    std::stringstream out;

    out << "\n" << group << ":\n";
    for(const Option *opt : opts) {
        out << make_option(opt, is_positional);
    }

    return out.str();
}

CLI11_INLINE std::string Formatter::make_positionals(const App *app) const {
    std::vector<const Option *> opts =
        app->get_options([](const Option *opt) { return !opt->get_group().empty() && opt->get_positional(); });

    if(opts.empty())
        return {};

    return make_group(get_label("Positionals"), true, opts);
}

CLI11_INLINE std::string Formatter::make_groups(const App *app, AppFormatMode mode) const {
    std::stringstream out;
    std::vector<std::string> groups = app->get_groups();

    // Options
    for(const std::string &group : groups) {
        std::vector<const Option *> opts = app->get_options([app, mode, &group](const Option *opt) {
            return opt->get_group() == group                     // Must be in the right group
                   && opt->nonpositional()                       // Must not be a positional
                   && (mode != AppFormatMode::Sub                // If mode is Sub, then
                       || (app->get_help_ptr() != opt            // Ignore help pointer
                           && app->get_help_all_ptr() != opt));  // Ignore help all pointer
        });
        if(!group.empty() && !opts.empty()) {
            out << make_group(group, false, opts);

            if(group != groups.back())
                out << "\n";
        }
    }

    return out.str();
}

CLI11_INLINE std::string Formatter::make_description(const App *app) const {
    std::string desc = app->get_description();
    auto min_options = app->get_require_option_min();
    auto max_options = app->get_require_option_max();
    if(app->get_required()) {
        desc += " REQUIRED ";
    }
    if((max_options == min_options) && (min_options > 0)) {
        if(min_options == 1) {
            desc += " \n[Exactly 1 of the following options is required]";
        } else {
            desc += " \n[Exactly " + std::to_string(min_options) + "options from the following list are required]";
        }
    } else if(max_options > 0) {
        if(min_options > 0) {
            desc += " \n[Between " + std::to_string(min_options) + " and " + std::to_string(max_options) +
                    " of the follow options are required]";
        } else {
            desc += " \n[At most " + std::to_string(max_options) + " of the following options are allowed]";
        }
    } else if(min_options > 0) {
        desc += " \n[At least " + std::to_string(min_options) + " of the following options are required]";
    }
    return (!desc.empty()) ? desc + "\n" : std::string{};
}

CLI11_INLINE std::string Formatter::make_usage(const App *app, std::string name) const {
    std::stringstream out;

    out << get_label("Usage") << ":" << (name.empty() ? "" : " ") << name;

    std::vector<std::string> groups = app->get_groups();

    // Print an Options badge if any options exist
    std::vector<const Option *> non_pos_options =
        app->get_options([](const Option *opt) { return opt->nonpositional(); });
    if(!non_pos_options.empty())
        out << " [" << get_label("OPTIONS") << "]";

    // Positionals need to be listed here
    std::vector<const Option *> positionals = app->get_options([](const Option *opt) { return opt->get_positional(); });

    // Print out positionals if any are left
    if(!positionals.empty()) {
        // Convert to help names
        std::vector<std::string> positional_names(positionals.size());
        std::transform(positionals.begin(), positionals.end(), positional_names.begin(), [this](const Option *opt) {
            return make_option_usage(opt);
        });

        out << " " << detail::join(positional_names, " ");
    }

    // Add a marker if subcommands are expected or optional
    if(!app->get_subcommands(
               [](const CLI::App *subc) { return ((!subc->get_disabled()) && (!subc->get_name().empty())); })
            .empty()) {
        out << " " << (app->get_require_subcommand_min() == 0 ? "[" : "")
            << get_label(app->get_require_subcommand_max() < 2 || app->get_require_subcommand_min() > 1 ? "SUBCOMMAND"
                                                                                                        : "SUBCOMMANDS")
            << (app->get_require_subcommand_min() == 0 ? "]" : "");
    }

    out << std::endl;

    return out.str();
}

CLI11_INLINE std::string Formatter::make_footer(const App *app) const {
    std::string footer = app->get_footer();
    if(footer.empty()) {
        return std::string{};
    }
    return "\n" + footer + "\n";
}

CLI11_INLINE std::string Formatter::make_help(const App *app, std::string name, AppFormatMode mode) const {

    // This immediately forwards to the make_expanded method. This is done this way so that subcommands can
    // have overridden formatters
    if(mode == AppFormatMode::Sub)
        return make_expanded(app);

    std::stringstream out;
    if((app->get_name().empty()) && (app->get_parent() != nullptr)) {
        if(app->get_group() != "Subcommands") {
            out << app->get_group() << ':';
        }
    }

    out << make_description(app);
    out << make_usage(app, name);
    out << make_positionals(app);
    out << make_groups(app, mode);
    out << make_subcommands(app, mode);
    out << make_footer(app);

    return out.str();
}

CLI11_INLINE std::string Formatter::make_subcommands(const App *app, AppFormatMode mode) const {
    std::stringstream out;

    std::vector<const App *> subcommands = app->get_subcommands({});

    // Make a list in definition order of the groups seen
    std::vector<std::string> subcmd_groups_seen;
    for(const App *com : subcommands) {
        if(com->get_name().empty()) {
            if(!com->get_group().empty()) {
                out << make_expanded(com);
            }
            continue;
        }
        std::string group_key = com->get_group();
        if(!group_key.empty() &&
           std::find_if(subcmd_groups_seen.begin(), subcmd_groups_seen.end(), [&group_key](std::string a) {
               return detail::to_lower(a) == detail::to_lower(group_key);
           }) == subcmd_groups_seen.end())
            subcmd_groups_seen.push_back(group_key);
    }

    // For each group, filter out and print subcommands
    for(const std::string &group : subcmd_groups_seen) {
        out << "\n" << group << ":\n";
        std::vector<const App *> subcommands_group = app->get_subcommands(
            [&group](const App *sub_app) { return detail::to_lower(sub_app->get_group()) == detail::to_lower(group); });
        for(const App *new_com : subcommands_group) {
            if(new_com->get_name().empty())
                continue;
            if(mode != AppFormatMode::All) {
                out << make_subcommand(new_com);
            } else {
                out << new_com->help(new_com->get_name(), AppFormatMode::Sub);
                out << "\n";
            }
        }
    }

    return out.str();
}

CLI11_INLINE std::string Formatter::make_subcommand(const App *sub) const {
    std::stringstream out;
    detail::format_help(out, sub->get_display_name(true), sub->get_description(), column_width_);
    return out.str();
}

CLI11_INLINE std::string Formatter::make_expanded(const App *sub) const {
    std::stringstream out;
    out << sub->get_display_name(true) << "\n";

    out << make_description(sub);
    if(sub->get_name().empty() && !sub->get_aliases().empty()) {
        detail::format_aliases(out, sub->get_aliases(), column_width_ + 2);
    }
    out << make_positionals(sub);
    out << make_groups(sub, AppFormatMode::Sub);
    out << make_subcommands(sub, AppFormatMode::Sub);

    // Drop blank spaces
    std::string tmp = detail::find_and_replace(out.str(), "\n\n", "\n");
    tmp = tmp.substr(0, tmp.size() - 1);  // Remove the final '\n'

    // Indent all but the first line (the name)
    return detail::find_and_replace(tmp, "\n", "\n  ") + "\n";
}

CLI11_INLINE std::string Formatter::make_option_name(const Option *opt, bool is_positional) const {
    if(is_positional)
        return opt->get_name(true, false);

    return opt->get_name(false, true);
}

CLI11_INLINE std::string Formatter::make_option_opts(const Option *opt) const {
    std::stringstream out;

    if(!opt->get_option_text().empty()) {
        out << " " << opt->get_option_text();
    } else {
        if(opt->get_type_size() != 0) {
            if(!opt->get_type_name().empty())
                out << " " << get_label(opt->get_type_name());
            if(!opt->get_default_str().empty())
                out << " [" << opt->get_default_str() << "] ";
            if(opt->get_expected_max() == detail::expected_max_vector_size)
                out << " ...";
            else if(opt->get_expected_min() > 1)
                out << " x " << opt->get_expected();

            if(opt->get_required())
                out << " " << get_label("REQUIRED");
        }
        if(!opt->get_envname().empty())
            out << " (" << get_label("Env") << ":" << opt->get_envname() << ")";
        if(!opt->get_needs().empty()) {
            out << " " << get_label("Needs") << ":";
            for(const Option *op : opt->get_needs())
                out << " " << op->get_name();
        }
        if(!opt->get_excludes().empty()) {
            out << " " << get_label("Excludes") << ":";
            for(const Option *op : opt->get_excludes())
                out << " " << op->get_name();
        }
    }
    return out.str();
}

CLI11_INLINE std::string Formatter::make_option_desc(const Option *opt) const { return opt->get_description(); }

CLI11_INLINE std::string Formatter::make_option_usage(const Option *opt) const {
    // Note that these are positionals usages
    std::stringstream out;
    out << make_option_name(opt, true);
    if(opt->get_expected_max() >= detail::expected_max_vector_size)
        out << "...";
    else if(opt->get_expected_max() > 1)
        out << "(" << opt->get_expected() << "x)";

    return opt->get_required() ? out.str() : "[" + out.str() + "]";
}


} // namespace CLI

} // namespace pxr_CLI

PXR_NAMESPACE_CLOSE_SCOPE