1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <functional>
10 
11 // struct is_placeholder
12 
13 #include <functional>
14 #include "test_macros.h"
15 
16 template <int Expected, class T>
17 void
18 test(const T&)
19 {
20     static_assert(std::is_placeholder<T>::value == Expected, "");
21     LIBCPP_STATIC_ASSERT(std::is_placeholder<T&>::value == Expected, "");
22     LIBCPP_STATIC_ASSERT(std::is_placeholder<const T>::value == Expected, "");
23     LIBCPP_STATIC_ASSERT(std::is_placeholder<const T&>::value == Expected, "");
24 
25 #if TEST_STD_VER > 14
26     static_assert(std::is_placeholder_v<T> == Expected, "");
27     LIBCPP_STATIC_ASSERT(std::is_placeholder_v<T&> == Expected, "");
28     LIBCPP_STATIC_ASSERT(std::is_placeholder_v<const T> == Expected, "");
29     LIBCPP_STATIC_ASSERT(std::is_placeholder_v<const T&> == Expected, "");
30 #endif
31 }
32 
33 struct C {};
34 
35 int main(int, char**)
36 {
37     test<1>(std::placeholders::_1);
38     test<2>(std::placeholders::_2);
39     test<3>(std::placeholders::_3);
40     test<4>(std::placeholders::_4);
41     test<5>(std::placeholders::_5);
42     test<6>(std::placeholders::_6);
43     test<7>(std::placeholders::_7);
44     test<8>(std::placeholders::_8);
45     test<9>(std::placeholders::_9);
46     test<10>(std::placeholders::_10);
47     test<0>(4);
48     test<0>(5.5);
49     test<0>('a');
50     test<0>(C());
51 
52   return 0;
53 }
54