整理

include/boost/iterator/iterator_traits.hpp

@@ -0,0 +1,68 @@
+// Copyright David Abrahams 2003.
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#ifndef ITERATOR_TRAITS_DWA200347_HPP
+#define ITERATOR_TRAITS_DWA200347_HPP
+
+#include <iterator>
+
+namespace boost {
+namespace iterators {
+
+template< typename Iterator >
+using iterator_value_t = typename std::iterator_traits< Iterator >::value_type;
+
+template< typename Iterator >
+struct iterator_value
+{
+    using type = iterator_value_t< Iterator >;
+};
+
+template< typename Iterator >
+using iterator_reference_t = typename std::iterator_traits< Iterator >::reference;
+
+template< typename Iterator >
+struct iterator_reference
+{
+    using type = iterator_reference_t< Iterator >;
+};
+
+template< typename Iterator >
+using iterator_pointer_t = typename std::iterator_traits< Iterator >::pointer;
+
+template< typename Iterator >
+struct iterator_pointer
+{
+    using type = iterator_pointer_t< Iterator >;
+};
+
+template< typename Iterator >
+using iterator_difference_t = typename std::iterator_traits< Iterator >::difference_type;
+
+template< typename Iterator >
+struct iterator_difference
+{
+    using type = iterator_difference_t< Iterator >;
+};
+
+template< typename Iterator >
+using iterator_category_t = typename std::iterator_traits< Iterator >::iterator_category;
+
+template< typename Iterator >
+struct iterator_category
+{
+    using type = iterator_category_t< Iterator >;
+};
+
+} // namespace iterators
+
+using iterators::iterator_value;
+using iterators::iterator_reference;
+using iterators::iterator_pointer;
+using iterators::iterator_difference;
+using iterators::iterator_category;
+
+} // namespace boost
+
+#endif // ITERATOR_TRAITS_DWA200347_HPP