Examples

Full text of example from tutorial

#include <iostream>
#include "ArgParse/argparse.h"

int main(int argc, char** argv)
{
    auto parser = argparse::ArgumentParser("Program name").SetDescription("Description of program");
    parser.AddArgument(argparse::CreateNamedArgument()
        .SetLongName("numbers")
        .SetAnyNumberOfArgumentsButAtleastOne()
        .SetType(argparse::ArgTypeCast::e_int));
    parser.AddArgument(argparse::CreateNamedArgument()
        .SetLongName("some_boring_long_name")
        .SetAnyNumberOfArgumentsButAtleastOne()
        .SetType(argparse::ArgTypeCast::e_int)
        .SetHelp("some_boring_long_name description with some important information for user.")
        .SetRequired(false));

    auto obj = parser.ParseArgs(argc, argv);
    if (obj.IsArgValid())
    {
        auto arg = obj.GetArg("numbers");
        if (arg.GetArgumentExists())
        {
            for (auto& el : arg.GetAsVecInt())
            {
                std::cout << el << std::endl;
            }
        }
    }
    else
    {
        std::string help = parser.GetHelp(80);
        std::cout << obj.GetErrorString() << std::endl;
        std::cout << help << std::endl;
    }

    return 0;
}

This exmaple will create program with keys -n, --number, -s, --some_boring_long_name, -h and --help. Help will be autogenerated. The types of numbers and some_boring_long_name are integers with count from 1 to infinite.

Typical output without any arguments:

main.cpp [-n,--numbers [n ...] ] [-s,--some_boring_long_name [s ...] ] -h,--help
Description of program

optional arguments:

-n,--numbers            some numbers description with some important information
                        for user. Type: INT. Args count: at least one.
-s,--some_boring_long_name
                        some_boring_long_name description with some important information
                        for user. Type: INT. Args count: at least one.
-h,--help               Show help!

Note actually terminal cannot get infinite numbers of arguments. In most cases maximum length of all input that terminal can pass is limited with 8 kb.

Same thing but shorter way

#include <iostream>
#include "ArgParse/argparse.h"

int main(int argc, char** argv)
{
    auto parser = argparse::ArgumentParser(__FILE__).SetDescription("Description of program");

    parser.AddArgument(argparse::CreateNamedArgument("n", "numbers", argparse::kFromOneToInfinteArgCount,
        argparse::ArgTypeCast::e_int, false, 
        "some numbers description with some important information for user."));
    parser.AddArgument(argparse::CreateNamedArgument("s", "some_boring_long_name", argparse::kFromOneToInfinteArgCount,
        argparse::ArgTypeCast::e_int, false, 
        "some_boring_long_name description with some important information for user."));
    auto obj = parser.ParseArgs(argc, argv);
    if (obj.IsArgValid())
    {
        auto arg = obj.GetArg("numbers");
        if (arg.GetArgumentExists())
        {
            for (auto& el : arg.GetAsVecInt())
            {
                std::cout << el << std::endl;
            }
        }
    }
    else
    {
        std::string help = parser.GetHelp(80);
        std::cout << obj.GetErrorString() << std::endl;
        std::cout << help << std::endl;
    }

    return 0;
}

Making 1 required argument, with 1 required value

generic -h, --help is suppressed

example compiles for c++17 and uses std::any approach

#include <iostream>
#include "ArgParse/argparse.h"

int main(int argc, char** argv)
{
    auto parser = argparse::ArgumentParser("main").SetDescription("ArgParse example");

    parser.AddArgument(argparse::CreateNamedArgument("b", "b_key", 1,  argparse::ArgTypeCast::e_int, true, 
        R"=(some "b_key" description with some important information for user)="));

    parser.SetAddHelp(false);

    auto obj = parser.ParseArgs(argc, argv);
    if (obj.IsArgValid())
    {
        auto arg = obj.GetArg("b_key");
        std::cout << arg.Get().type().name() << ": " << std::any_cast<int>(arg.Get()) << std::endl;
    }
    else
    {
        std::string help = parser.GetHelp(80);
        std::cout << obj.GetErrorString() << std::endl;
        std::cout << help << std::endl;
    }

    return 0;
}

You can change 1 to 0 from this example. It will be flag, and you cannot access to it's content.