Function main

examples/date_validator.cpp:28–40

    "datetime[%Y-%m-%dT%H:%M:%S]");

int main(int argc, char **argv) {

    CLI::App app("custom validator testing");

    std::string value;
    app.add_option("--time", value, "enter a date in iso8601 format")->check(ISO8601)->required();

    CLI11_PARSE(app, argc, argv);

    std::cout << "date given = " << value << '\n';

    return 0;
}