Function getopt_long_only

library/cpp/getopt/small/posix_getopt.cpp:66–69

    }

    int getopt_long_only(int argc, char* const* argv, const char* optstring,
                         const struct option* longopts, int* longindex) {
        return getopt_long_impl(argc, argv, optstring, longopts, longindex, true);
    }

    // XXX: leading colon is not supported
    // XXX: updating optind by client is not supported