// // cpp03/require_concept_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_concept.hpp" #include template struct prop { static const bool is_requirable_concept = true; }; template struct object { template object require_concept(prop) const { return object(); } }; namespace asio { template struct is_applicable_property, prop > { static const bool value = true; }; namespace traits { template struct require_concept_member, prop > { static const bool is_valid = true; static const bool is_noexcept = true; typedef object result_type; }; } // namespace traits } // namespace asio int main() { object<1> o1 = {}; object<2> o2 = asio::require_concept(o1, prop<2>()); (void)o2; const object<1> o3 = {}; object<2> o4 = asio::require_concept(o3, prop<2>()); (void)o4; }