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 // <functional> 10 11 // template <class T> 12 // struct hash 13 // : public unary_function<T, size_t> 14 // { 15 // size_t operator()(T val) const; 16 // }; 17 18 // Not very portable 19 20 #include <string> 21 #include <cassert> 22 #include <type_traits> 23 24 #include "test_macros.h" 25 26 template <class T> 27 void 28 test() 29 { 30 typedef std::hash<T> H; 31 static_assert((std::is_same<typename H::argument_type, T>::value), "" ); 32 static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" ); 33 ASSERT_NOEXCEPT(H()(T())); 34 35 H h; 36 std::string g1 = "1234567890"; 37 std::string g2 = "1234567891"; 38 T s1(g1.begin(), g1.end()); 39 T s2(g2.begin(), g2.end()); 40 assert(h(s1) != h(s2)); 41 } 42 43 int main(int, char**) 44 { 45 test<std::string>(); 46 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L 47 test<std::u8string>(); 48 #endif 49 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS 50 test<std::u16string>(); 51 test<std::u32string>(); 52 #endif // _LIBCPP_HAS_NO_UNICODE_CHARS 53 test<std::wstring>(); 54 55 return 0; 56 } 57