1//
2// cpp14/require_concept_member.cpp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6//
7// Distributed under the Boost Software License, Version 1.0. (See accompanying
8// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9//
10
11#include <boost/asio/require_concept.hpp>
12#include <cassert>
13
14template <int>
15struct prop
16{
17 template <typename> static constexpr bool is_applicable_property_v = true;
18 static constexpr bool is_requirable_concept = true;
19};
20
21template <int>
22struct object
23{
24 template <int N>
25 constexpr object<N> require_concept(prop<N>) const
26 {
27 return object<N>();
28 }
29};
30
31int main()
32{
33 object<1> o1 = {};
34 object<2> o2 = boost::asio::require_concept(o1, prop<2>());
35 (void)o2;
36
37 const object<1> o3 = {};
38 object<2> o4 = boost::asio::require_concept(o3, prop<2>());
39 (void)o4;
40
41 constexpr object<2> o5 = boost::asio::require_concept(object<1>(), prop<2>());
42 (void)o5;
43}
44

source code of boost/libs/asio/test/properties/cpp14/require_concept_member.cpp