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 Iter> 13 // struct iterator_traits 14 // { 15 // typedef typename Iter::difference_type difference_type; 16 // typedef typename Iter::value_type value_type; 17 // typedef typename Iter::pointer pointer; 18 // typedef typename Iter::reference reference; 19 // typedef typename Iter::iterator_category iterator_category; 20 // }; 21 22 #include <iterator> 23 #include <type_traits> 24 25 struct A {}; 26 27 struct test_iterator 28 { 29 typedef int difference_type; 30 typedef A value_type; 31 typedef A* pointer; 32 typedef A& reference; 33 typedef std::forward_iterator_tag iterator_category; 34 }; 35 36 int main() 37 { 38 typedef std::iterator_traits<test_iterator> It; 39 static_assert((std::is_same<It::difference_type, int>::value), ""); 40 static_assert((std::is_same<It::value_type, A>::value), ""); 41 static_assert((std::is_same<It::pointer, A*>::value), ""); 42 static_assert((std::is_same<It::iterator_category, std::forward_iterator_tag>::value), ""); 43 } 44