Function measure_one

lib/catch2/catch.hpp:6861–6863

        namespace Detail {
            template <typename Clock, typename Fun>
            TimingOf<Clock, Fun, int> measure_one(Fun&& fun, int iters, std::false_type) {
                return Detail::measure<Clock>(fun, iters);
            }
            template <typename Clock, typename Fun>
            TimingOf<Clock, Fun, Chronometer> measure_one(Fun&& fun, int iters, std::true_type) {
                Detail::ChronometerModel<Clock> meter;