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 <bitset> 22 #include <cassert> 23 #include <type_traits> 24 25 template <std::size_t N> 26 void 27 test() 28 { 29 typedef std::bitset<N> T; 30 typedef std::hash<T> H; 31 static_assert((std::is_base_of<std::unary_function<T, std::size_t>, 32 H>::value), ""); 33 H h; 34 T bs(static_cast<unsigned long long>(N)); 35 assert(h(bs) == N); 36 } 37 38 int main() 39 { 40 test<0>(); 41 test<10>(); 42 test<100>(); 43 test<1000>(); 44 } 45