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 _Tp>
24 struct has_value_type
25 {
26 private:
27     struct two {char lx; char lxx;};
28     template <class _Up> static two test(...);
29     template <class _Up> static char test(typename _Up::value_type* = 0);
30 public:
31     static const bool value = sizeof(test<_Tp>(0)) == 1;
32 };
33 
main()34 int main()
35 {
36     typedef std::iterator_traits<not_an_iterator> It;
37     static_assert(!(has_value_type<It>::value), "");
38 }
39