pointer.pass.cpp (1404B)
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 // template <class T> 13 // struct hash 14 // : public unary_function<T, size_t> 15 // { 16 // size_t operator()(T val) const; 17 // }; 18 19 // Not very portable 20 21 #include <functional> 22 #include <cassert> 23 #include <type_traits> 24 #include <limits> 25 26 #include "test_macros.h" 27 28 template <class T> 29 void 30 test() 31 { 32 typedef std::hash<T> H; 33 static_assert((std::is_same<typename H::argument_type, T>::value), "" ); 34 static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" ); 35 ASSERT_NOEXCEPT(H()(T())); 36 H h; 37 38 typedef typename std::remove_pointer<T>::type type; 39 type i; 40 type j; 41 assert(h(&i) != h(&j)); 42 } 43 44 // can't hash nullptr_t until C++17 45 void test_nullptr() 46 { 47 #if TEST_STD_VER > 14 48 typedef std::nullptr_t T; 49 typedef std::hash<T> H; 50 static_assert((std::is_same<typename H::argument_type, T>::value), "" ); 51 static_assert((std::is_same<typename H::result_type, std::size_t>::value), "" ); 52 ASSERT_NOEXCEPT(H()(T())); 53 #endif 54 } 55 56 int main() 57 { 58 test<int*>(); 59 test_nullptr(); 60 }