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// Make sure that we can hash enumeration values.
14
15#include "test_macros.h"
16
17#include <functional>
18#include <cassert>
19#include <type_traits>
20#include <limits>
21
22enum class Colors { red, orange, yellow, green, blue, indigo, violet };
23enum class Cardinals { zero, one, two, three, five=5 };
24enum class LongColors : short { red, orange, yellow, green, blue, indigo, violet };
25enum class ShortColors : long { red, orange, yellow, green, blue, indigo, violet };
26enum class EightBitColors : std::uint8_t { red, orange, yellow, green, blue, indigo, violet };
27
28enum Fruits { apple, pear, grape, mango, cantaloupe };
29
30template <class T>
31void
32test()
33{
34 typedef std::hash<T> H;
35#if TEST_STD_VER <= 17
36 static_assert((std::is_same<typename H::argument_type, T>::value), "");
37 static_assert((std::is_same<typename H::result_type, std::size_t>::value), "");
38#endif
39 ASSERT_NOEXCEPT(H()(T()));
40 typedef typename std::underlying_type<T>::type under_type;
41
42 H h1;
43 std::hash<under_type> h2;
44 for (int i = 0; i <= 5; ++i)
45 {
46 T t(static_cast<T> (i));
47 const bool small = std::integral_constant<bool, sizeof(T) <= sizeof(std::size_t)>::value; // avoid compiler warnings
48 if (small)
49 assert(h1(t) == h2(static_cast<under_type>(i)));
50 }
51}
52
53int main(int, char**)
54{
55 test<Cardinals>();
56
57 test<Colors>();
58 test<ShortColors>();
59 test<LongColors>();
60 test<EightBitColors>();
61
62 test<Fruits>();
63
64 return 0;
65}
66

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