1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <functional>
11 
12 // make sure that we can hash enumeration values
13 // Not very portable
14 
15 #include <__config>
16 
17 #if _LIBCPP_STD_VER > 11
18 
19 #include <functional>
20 #include <cassert>
21 #include <type_traits>
22 #include <limits>
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 : 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     static_assert((std::is_base_of<std::unary_function<T, std::size_t>,
37                                    std::hash<T> >::value), "");
38     typedef typename std::underlying_type<T>::type under_type;
39 
40     std::hash<T> h1;
41     std::hash<under_type> h2;
42     for (int i = 0; i <= 5; ++i)
43     {
44         T t(static_cast<T> (i));
45         if (sizeof(T) <= sizeof(std::size_t))
46             assert(h1(t) == h2(static_cast<under_type>(i)));
47     }
48 }
49 
50 int main()
51 {
52     test<Cardinals>();
53 
54     test<Colors>();
55     test<ShortColors>();
56     test<LongColors>();
57     test<EightBitColors>();
58 
59     test<Fruits>();
60 }
61 #else
62 int main () {}
63 #endif
64