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 // <iterator> 11 12 // template<class NotAnIterator> 13 // struct iterator_traits 14 // { 15 // }; 16 17 #include <iterator> 18 19 struct not_an_iterator 20 { 21 }; 22 23 template <class T> 24 struct has_value_type 25 { 26 private: 27 struct two {char lx; char lxx;}; 28 template <class U> static two test(...); 29 template <class U> static char test(typename U::value_type* = 0); 30 public: 31 static const bool value = sizeof(test<T>(0)) == 1; 32 }; 33 main()34int main() 35 { 36 typedef std::iterator_traits<not_an_iterator> It; 37 static_assert(!(has_value_type<It>::value), ""); 38 } 39