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 #if __cplusplus >= 201402L
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
test()32 test()
33 {
34 typedef std::hash<T> H;
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 typedef typename std::underlying_type<T>::type under_type;
38
39 H h1;
40 std::hash<under_type> h2;
41 for (int i = 0; i <= 5; ++i)
42 {
43 T t(static_cast<T> (i));
44 if (sizeof(T) <= sizeof(std::size_t))
45 assert(h1(t) == h2(static_cast<under_type>(i)));
46 }
47 }
48
main()49 int main()
50 {
51 test<Cardinals>();
52
53 test<Colors>();
54 test<ShortColors>();
55 test<LongColors>();
56 test<EightBitColors>();
57
58 test<Fruits>();
59 }
60 #else
main()61 int main () {}
62 #endif
63