libcxx/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <iterator>
  10
  11 // template<class Iter>
  12 // struct iterator_traits
  13 // {
  14 //   typedef typename Iter::difference_type difference_type;
  15 //   typedef typename Iter::value_type value_type;
  16 //   typedef typename Iter::pointer pointer;
  17 //   typedef typename Iter::reference reference;
  18 //   typedef typename Iter::iterator_category iterator_category;
  19 // };
  20
  21 #include <iterator>
  22 #include <type_traits>
  23
  24 #include "test_macros.h"
  25
  26 struct A {};
  27
  28 struct test_iterator
  29 {
  30     typedef int                       difference_type;
  31     typedef A                         value_type;
  32     typedef A*                        pointer;
  33     typedef A&                        reference;
  34     typedef std::forward_iterator_tag iterator_category;
  35 };
  36
  37 int main(int, char**)
  38 {
  39     typedef std::iterator_traits<test_iterator> It;
  40     static_assert((std::is_same<It::difference_type, int>::value), "");
  41     static_assert((std::is_same<It::value_type, A>::value), "");
  42     static_assert((std::is_same<It::pointer, A*>::value), "");
  43     static_assert((std::is_same<It::reference, A&>::value), "");
  44     static_assert((std::is_same<It::iterator_category, std::forward_iterator_tag>::value), "");
  45
  46   return 0;
  47 }