compat.argparse

// Behavioral test — compat.argparse parses a command line, it does not merely
// include.
//
// argv is written by hand rather than taken from the runner, so the assertions
// are about argparse's behaviour and not about how `mcpp test` invokes a
// binary. No `import std;`: argparse.hpp is a textual header over the standard
// library.
#include <argparse/argparse.hpp>

#include <iostream>
#include <string>
#include <vector>

int main() {
    argparse::ArgumentParser program("renderer", "0.1.0");
    program.add_argument("model").help("path to the glTF model");
    program.add_argument("--width").default_value(1280).scan<'i', int>();
    program.add_argument("--validate").default_value(false).implicit_value(true);

    const std::vector<std::string> argv{"renderer", "scene.gltf", "--width", "1920", "--validate"};
    try {
        program.parse_args(argv);
// …