Cliar

A Command Line Interface Argument parser based on Reflection.

Usage

#include <cliar.hpp>
#include <fmt/core.h>

// Define a struct of `option<T, names...>`
struct cli_args
{
    cliar::option<bool> verbose = false;  // simple boolean flag
    cliar::option<<std::optional<bool>> help = false;  // optional flag with comment

    cliar::option<int, "both option names are deduced"> this_deduces_both;
    cliar::option<float, "-l", "short name fixed, long name deduced"> deduced_long_name;
    cliar::option<std::string, "--short", "short name deduced, long name fixed"> deduce_short_name;
    cliar::option<std::optional<int>, "-b", "--both", "both option names fixed"> set_both = 100;
    cliar::option<std::optional<float>, "-", "--only-long", "disable short option"> only_long;
    cliar::option<std::optional<std::string>, "--", "-o", "disable long option"> only_short;
    // cliar::option<int, "--", "-", "can't disable both long and short"> i_wont_compile;
};

int main(int argc, char * argv[])
{
    auto args = std::span{argv, argv + argc};
    // Parse the command line option
    auto result = cliar::parse<cli_args>(std::span{argv, argv + argc});

    // Eventually print the help message
    if (*result.help) {
        fmt::print("{}\n", cliar::help<cli_args>());
        return 0;
    }

    // Access the members and do your stuff
    fmt::print("{}\n", *result.only_short);
}

Dependencies

Cliar only depends on fmt (eventually provided via conan) and reflect (bundled in the library as header). Note that the provided header for reflect is slightly modified to make it work with -Wshadow under GCC.