1//
2// cpp11/can_query_not_applicable_static.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/query.hpp>
12#include <cassert>
13
14struct prop
15{
16};
17
18struct object
19{
20};
21
22namespace boost {
23namespace asio {
24namespace traits {
25
26template<>
27struct static_query<object, prop>
28{
29 static constexpr bool is_valid = true;
30 static constexpr bool is_noexcept = true;
31 typedef int result_type;
32 static constexpr int value() { return 123; }
33};
34
35} // namespace traits
36} // namespace asio
37} // namespace boost
38
39int main()
40{
41 static_assert(!boost::asio::can_query<object, prop>::value, "");
42 static_assert(!boost::asio::can_query<const object, prop>::value, "");
43}
44

source code of boost/libs/asio/test/properties/cpp11/can_query_not_applicable_static.cpp