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 static_assert((std::is_base_of<std::unary_function<T, std::size_t>, 31 std::hash<T> >::value), ""); 32 std::hash<T> h; 33 typedef typename std::remove_pointer<T>::type type; 34 type i; 35 type j; 36 assert(h(&i) != h(&j)); 37 } 38 main()39int main() 40 { 41 test<int*>(); 42 } 43