// // cpp03/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() { object<1> o1 = {}; object<2> o2 = asio::require(o1, prop<2>()); object<3> o3 = asio::require(o1, prop<2>(), prop<3>()); object<4> o4 = asio::require(o1, prop<2>(), prop<3>(), prop<4>()); (void)o2; (void)o3; (void)o4; const object<1> o5 = {}; object<2> o6 = asio::require(o5, prop<2>()); object<3> o7 = asio::require(o5, prop<2>(), prop<3>()); object<4> o8 = asio::require(o5, prop<2>(), prop<3>(), prop<4>()); (void)o6; (void)o7; (void)o8; }