Method operator()

src/rpp/rpp/sources/from.hpp:140–151

    {
        template<typename Callable>
        auto operator()(Callable&& fn) const
        {
            if constexpr (std::same_as<utils::decayed_invoke_result_t<Callable>, void>)
            {
                fn();
                return rpp::utils::none{};
            }
            else
            {
                return fn();
            }
        }
    };
} // namespace rpp::details