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// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
10
11// <functional>
12
13// template <class T>
14// struct hash
15// : public unary_function<T, size_t>
16// {
17// size_t operator()(T val) const;
18// };
19
20// Not very portable
21
22#include <cassert>
23#include <cstddef>
24#include <functional>
25#include <type_traits>
26
27#include "test_macros.h"
28
29template <class T>
30void
31test()
32{
33 typedef std::hash<T> H;
34#if TEST_STD_VER <= 17
35 static_assert((std::is_same<typename H::argument_type, T>::value), "");
36 static_assert((std::is_same<typename H::result_type, std::size_t>::value), "");
37#endif
38 ASSERT_NOEXCEPT(H()(T()));
39 H h;
40
41 typedef typename std::remove_pointer<T>::type type;
42 type i;
43 type j;
44 assert(h(&i) != h(&j));
45}
46
47// can't hash nullptr_t until C++17
48void test_nullptr()
49{
50#if TEST_STD_VER > 14
51 typedef std::nullptr_t T;
52 typedef std::hash<T> H;
53#if TEST_STD_VER <= 17
54 static_assert((std::is_same<typename H::argument_type, T>::value), "" );
55 static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" );
56#endif
57 ASSERT_NOEXCEPT(H()(T()));
58#endif
59}
60
61int main(int, char**)
62{
63 test<int*>();
64 test_nullptr();
65
66 return 0;
67}
68

source code of libcxx/test/std/utilities/function.objects/unord.hash/pointer.pass.cpp