#ifndef ASYNC_MQTT5_TRAITS_HPP #define ASYNC_MQTT5_TRAITS_HPP #include #include #include #include namespace async_mqtt5 { template constexpr bool is_optional_impl = false; template constexpr bool is_optional_impl> = true; template constexpr bool is_optional = is_optional_impl>; template typename> constexpr bool is_specialization = false; template