// // cpp03/can_require_member.cpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #include "asio/require.hpp" #include template struct prop { static const bool is_requirable = true; }; template struct object { template object require(prop) const { return object(); } }; namespace asio { template struct is_applicable_property, prop > { static const bool value = true; }; namespace traits { template struct require_member, prop > { static const bool is_valid = true; static const bool is_noexcept = true; typedef object result_type; }; } // namespace traits } // namespace asio int main() { assert((asio::can_require, prop<2> >::value)); assert((asio::can_require, prop<2>, prop<3> >::value)); assert((asio::can_require, prop<2>, prop<3>, prop<4> >::value)); assert((asio::can_require, prop<2> >::value)); assert((asio::can_require, prop<2>, prop<3> >::value)); assert((asio::can_require, prop<2>, prop<3>, prop<4> >::value)); }