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 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 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 61 int main () {} 62 #endif 63
