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 // UNSUPPORTED: c++03, c++11
10 
11 // <propagate_const>
12 
13 // template <class T> struct hash<experimental::fundamentals_v2::propagate_const<T>>;
14 
15 #include <experimental/propagate_const>
16 #include <cassert>
17 #include <cstddef>
18 #include <functional>
19 
20 #include "test_macros.h"
21 #include "propagate_const_helpers.h"
22 
23 using std::experimental::propagate_const;
24 
25 template <>
26 struct std::hash<X> {
27   typedef X first_argument_type;
28 
29   std::size_t operator()(const first_argument_type&) const { return 99; }
30 };
31 
32 int main(int, char**) {
33 
34   typedef propagate_const<X> P;
35 
36   P p(1);
37 
38   auto h = std::hash<P>();
39 
40   assert(h(p)==99);
41 
42   return 0;
43 }
44