xref: /llvm-project/libcxx/test/std/utilities/function.objects/unord.hash/enum.pass.cpp (revision 09e3a360581dc36d0820d3fb6da9bd7cfed87b5d)
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 <functional>
16 #include <cassert>
17 #include <cstddef>
18 #include <cstdint>
19 #include <limits>
20 #include <type_traits>
21 
22 #include "test_macros.h"
23 
24 enum class Colors { red, orange, yellow, green, blue, indigo, violet };
25 enum class Cardinals { zero, one, two, three, five=5 };
26 enum class LongColors : short { red, orange, yellow, green, blue, indigo, violet };
27 enum class ShortColors : long { red, orange, yellow, green, blue, indigo, violet };
28 enum class EightBitColors : std::uint8_t { red, orange, yellow, green, blue, indigo, violet };
29 
30 enum Fruits { apple, pear, grape, mango, cantaloupe };
31 
32 template <class T>
33 void
34 test()
35 {
36     typedef std::hash<T> H;
37 #if TEST_STD_VER <= 17
38     static_assert((std::is_same<typename H::argument_type, T>::value), "");
39     static_assert((std::is_same<typename H::result_type, std::size_t>::value), "");
40 #endif
41     ASSERT_NOEXCEPT(H()(T()));
42     typedef typename std::underlying_type<T>::type under_type;
43 
44     H h1;
45     std::hash<under_type> h2;
46     for (int i = 0; i <= 5; ++i)
47     {
48         T t(static_cast<T> (i));
49         const bool small = std::integral_constant<bool, sizeof(T) <= sizeof(std::size_t)>::value; // avoid compiler warnings
50         if (small)
51             assert(h1(t) == h2(static_cast<under_type>(i)));
52     }
53 }
54 
55 int main(int, char**)
56 {
57     test<Cardinals>();
58 
59     test<Colors>();
60     test<ShortColors>();
61     test<LongColors>();
62     test<EightBitColors>();
63 
64     test<Fruits>();
65 
66   return 0;
67 }
68