xref: /llvm-project/libcxx/test/std/utilities/function.objects/unord.hash/enum.pass.cpp (revision 3f3abaf40ad5c732277e0d0be3c0e86b8ba49f34)
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 
22 enum class Colors { red, orange, yellow, green, blue, indigo, violet };
23 enum class Cardinals { zero, one, two, three, five=5 };
24 enum class LongColors : short { red, orange, yellow, green, blue, indigo, violet };
25 enum class ShortColors : long { red, orange, yellow, green, blue, indigo, violet };
26 enum class EightBitColors : uint8_t { red, orange, yellow, green, blue, indigo, violet };
27 
28 enum Fruits { apple, pear, grape, mango, cantaloupe };
29 
30 template <class T>
31 void
32 test()
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 
53 int 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