#include #include #include enum class Level : int { High, Medium, Low }; int main(int argc, char **argv) { CLI::App app; std::map map = {{"High", Level::High}, {"Medium", Level::Medium}, {"Low", Level::Low}}; Level level; app.add_option("-l,--level", level, "Level settings") ->required() ->transform(CLI::IsMember(map, CLI::ignore_case) | CLI::IsMember({Level::High, Level::Medium, Level::Low})); CLI11_PARSE(app, argc, argv); // CLI11's built in enum streaming can be used outside CLI11 like this: using namespace CLI::enums; std::cout << "Enum received: " << level << std::endl; return 0; }