test/std/iterators/predef.iterators/move.iterators/move.iterator/types.pass.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// <iterator>

// move_iterator

// Test nested types:

// template <InputIterator Iter>
// class move_iterator {
// public:
//   typedef Iter                  iterator_type;
//   typedef Iter::difference_type difference_type;
//   typedef Iter                  pointer;
//   typedef Iter::value_type      value_type;
//   typedef value_type&&          reference;
// };

#include <iterator>
#include <type_traits>

#include "test_macros.h"
#include "test_iterators.h"

template <class ValueType, class Reference>
struct DummyIt {
  typedef std::forward_iterator_tag iterator_category;
  typedef ValueType value_type;
  typedef std::ptrdiff_t difference_type;
  typedef ValueType* pointer;
  typedef Reference reference;
};

template <class It>
void
test()
{
    typedef std::move_iterator<It> R;
    typedef std::iterator_traits<It> T;
    static_assert((std::is_same<typename R::iterator_type, It>::value), "");
    static_assert((std::is_same<typename R::difference_type, typename T::difference_type>::value), "");
    static_assert((std::is_same<typename R::pointer, It>::value), "");
    static_assert((std::is_same<typename R::value_type, typename T::value_type>::value), "");
#if TEST_STD_VER >= 11
    static_assert((std::is_same<typename R::reference, typename R::value_type&&>::value), "");
#else
    static_assert((std::is_same<typename R::reference, typename T::reference>::value), "");
#endif
    static_assert((std::is_same<typename R::iterator_category, typename T::iterator_category>::value), "");
}

int main(int, char**)
{
    test<input_iterator<char*> >();
    test<forward_iterator<char*> >();
    test<bidirectional_iterator<char*> >();
    test<random_access_iterator<char*> >();
    test<char*>();
#if TEST_STD_VER >= 11
    {
        typedef DummyIt<int, int> T;
        typedef std::move_iterator<T> It;
        static_assert(std::is_same<It::reference, int>::value, "");
    }
    {
        typedef DummyIt<int, std::reference_wrapper<int> > T;
        typedef std::move_iterator<T> It;
        static_assert(std::is_same<It::reference, std::reference_wrapper<int> >::value, "");
    }
    {
        // Check that move_iterator uses whatever reference type it's given
        // when it's not a reference.
        typedef DummyIt<int, long > T;
        typedef std::move_iterator<T> It;
        static_assert(std::is_same<It::reference, long>::value, "");
    }
    {
        typedef DummyIt<int, int&> T;
        typedef std::move_iterator<T> It;
        static_assert(std::is_same<It::reference, int&&>::value, "");
    }
    {
        typedef DummyIt<int, int&&> T;
        typedef std::move_iterator<T> It;
        static_assert(std::is_same<It::reference, int&&>::value, "");
    }
#endif

  return 0;
}