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 // template <class T>
12 // struct hash
13 //     : public unary_function<T, size_t>
14 // {
15 //     size_t operator()(T val) const;
16 // };
17 
18 #include <bitset>
19 #include <cassert>
20 #include <type_traits>
21 
22 #include "test_macros.h"
23 
24 template <std::size_t N>
25 void
26 test()
27 {
28     typedef std::bitset<N> T;
29     typedef std::hash<T> H;
30     static_assert((std::is_same<typename H::argument_type, T>::value), "" );
31     static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" );
32     ASSERT_NOEXCEPT(H()(T()));
33 
34     H h;
35     T bs(static_cast<unsigned long long>(N));
36     const std::size_t result = h(bs);
37     LIBCPP_ASSERT(result == N);
38     ((void)result); // Prevent unused warning
39 }
40 
41 int main(int, char**)
42 {
43     test<0>();
44     test<10>();
45     test<100>();
46     test<1000>();
47 
48   return 0;
49 }
50