Merge pull request #1491 from divyegala/update-iterator-traits

thrust::iterator_traits to inherit from std::iterator_traits

thrust/iterator/iterator_traits.h

@@ -37,59 +37,11 @@
 
 THRUST_NAMESPACE_BEGIN
 
-namespace detail
-{
-
-template <typename T, typename = void>
-struct iterator_traits_impl {};
-
-template <typename T>
-struct iterator_traits_impl<
-  T
-, typename voider<
-    typename T::difference_type
-  , typename T::value_type
-  , typename T::pointer
-  , typename T::reference
-  , typename T::iterator_category
-  >::type 
->
-{
-  typedef typename T::difference_type difference_type;
-  typedef typename T::value_type value_type;
-  typedef typename T::pointer pointer;
-  typedef typename T::reference reference;
-  typedef typename T::iterator_category iterator_category;
-};
-
-} // namespace detail
-
 /*! \p iterator_traits is a type trait class that provides a uniform
  *  interface for querying the properties of iterators at compile-time.
  */
 template <typename T>
-struct iterator_traits : detail::iterator_traits_impl<T> {};
-
-// traits are specialized for pointer types
-template<typename T>
-  struct iterator_traits<T*>
-{
-  typedef std::ptrdiff_t difference_type;
-  typedef T value_type;
-  typedef T* pointer;
-  typedef T& reference;
-  typedef std::random_access_iterator_tag iterator_category;
-};
-
-template<typename T>
-  struct iterator_traits<const T*>
-{
-  typedef std::ptrdiff_t difference_type;
-  typedef T value_type;
-  typedef const T* pointer;
-  typedef const T& reference;
-  typedef std::random_access_iterator_tag iterator_category;
-}; // end iterator_traits
+struct iterator_traits : std::iterator_traits<T> {};
 
 template<typename Iterator> struct iterator_value;