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 template <class T> 27 void test()28test() 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 H h; 34 35 typedef typename std::remove_pointer<T>::type type; 36 type i; 37 type j; 38 assert(h(&i) != h(&j)); 39 } 40 main()41int main() 42 { 43 test<int*>(); 44 } 45