// Functions used by iterators -*- C++ -*-
-// Copyright (C) 2001 Free Software Foundation, Inc.
+// Copyright (C) 2001, 2002 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
* purpose. It is provided "as is" without express or implied warranty.
*/
-/* NOTE: This is an internal header file, included by other STL headers.
- * You should not attempt to use it directly.
+/** @file stl_iterator_base_funcs.h
+ * This is an internal header file, included by other library headers.
+ * You should not attempt to use it directly.
+ *
+ * This file contains all of the general iterator-related utility
+ * functions, such as distance() and advance().
*/
-#ifndef __SGI_STL_INTERNAL_ITERATOR_BASE_FUNCS_H
-#define __SGI_STL_INTERNAL_ITERATOR_BASE_FUNCS_H
-
-// This file contains all of the general iterator-related utility
-// functions, such as distance() and advance().
-// The internal file stl_iterator.h contains predefined iterators,
-// such as front_insert_iterator and istream_iterator.
+#ifndef __GLIBCPP_INTERNAL_ITERATOR_BASE_FUNCS_H
+#define __GLIBCPP_INTERNAL_ITERATOR_BASE_FUNCS_H
#pragma GCC system_header
#include <bits/concept_check.h>
namespace std
{
-
-// There are two signatures for distance. In addition to the one taking
-// two iterators and returning a result, there is another taking two
-// iterators and a reference-to-result variable, and returning nothing.
-// The latter seems to be an SGI extension. -- pedwards
-template <class _InputIterator, class _Distance>
-inline void __distance(_InputIterator __first, _InputIterator __last,
- _Distance& __n, input_iterator_tag)
-{
- // concept requirements
- __glibcpp_function_requires(_InputIteratorConcept<_InputIterator>);
- while (__first != __last) { ++__first; ++__n; }
-}
-
-template <class _RandomAccessIterator, class _Distance>
-inline void __distance(_RandomAccessIterator __first,
- _RandomAccessIterator __last,
- _Distance& __n, random_access_iterator_tag)
-{
- // concept requirements
- __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>);
- __n += __last - __first;
-}
-
-template <class _InputIterator, class _Distance>
-inline void distance(_InputIterator __first,
- _InputIterator __last, _Distance& __n)
-{
- // concept requirements -- taken care of in __distance
- __distance(__first, __last, __n, iterator_category(__first));
-}
-
-template <class _InputIterator>
-inline typename iterator_traits<_InputIterator>::difference_type
-__distance(_InputIterator __first, _InputIterator __last, input_iterator_tag)
-{
- // concept requirements
- __glibcpp_function_requires(_InputIteratorConcept<_InputIterator>);
- typename iterator_traits<_InputIterator>::difference_type __n = 0;
- while (__first != __last) {
- ++__first; ++__n;
- }
- return __n;
-}
-
-template <class _RandomAccessIterator>
-inline typename iterator_traits<_RandomAccessIterator>::difference_type
-__distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
- random_access_iterator_tag)
-{
- // concept requirements
- __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>);
- return __last - __first;
-}
-
-template <class _InputIterator>
-inline typename iterator_traits<_InputIterator>::difference_type
-distance(_InputIterator __first, _InputIterator __last)
-{
- // concept requirements -- taken care of in __distance
- typedef typename iterator_traits<_InputIterator>::iterator_category
- _Category;
- return __distance(__first, __last, _Category());
-}
-
-template <class _InputIter, class _Distance>
-inline void __advance(_InputIter& __i, _Distance __n, input_iterator_tag)
-{
- // concept requirements
- __glibcpp_function_requires(_InputIteratorConcept<_InputIter>);
- while (__n--) ++__i;
-}
-
-template <class _BidirectionalIterator, class _Distance>
-inline void __advance(_BidirectionalIterator& __i, _Distance __n,
- bidirectional_iterator_tag)
-{
- // concept requirements
-__glibcpp_function_requires(_BidirectionalIteratorConcept<_BidirectionalIterator>);
- if (__n > 0)
- while (__n--) ++__i;
- else
- while (__n++) --__i;
-}
-
-template <class _RandomAccessIterator, class _Distance>
-inline void __advance(_RandomAccessIterator& __i, _Distance __n,
- random_access_iterator_tag)
-{
- // concept requirements
- __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>);
- __i += __n;
-}
-
-template <class _InputIterator, class _Distance>
-inline void advance(_InputIterator& __i, _Distance __n)
-{
- // concept requirements -- taken care of in __advance
- __advance(__i, __n, iterator_category(__i));
-}
-
+ template<typename _InputIterator>
+ inline typename iterator_traits<_InputIterator>::difference_type
+ __distance(_InputIterator __first, _InputIterator __last,
+ input_iterator_tag)
+ {
+ // concept requirements
+ __glibcpp_function_requires(_InputIteratorConcept<_InputIterator>)
+
+ typename iterator_traits<_InputIterator>::difference_type __n = 0;
+ while (__first != __last) {
+ ++__first; ++__n;
+ }
+ return __n;
+ }
+
+ template<typename _RandomAccessIterator>
+ inline typename iterator_traits<_RandomAccessIterator>::difference_type
+ __distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
+ random_access_iterator_tag)
+ {
+ // concept requirements
+ __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>)
+ return __last - __first;
+ }
+
+ /**
+ * @brief A generalization of pointer arithmetic.
+ * @param first An input iterator.
+ * @param last An input iterator.
+ * @return The distance between them.
+ *
+ * Returns @c n such that first + n == last. This requires that @p last
+ * must be reachable from @p first. Note that @c n may be negative.
+ *
+ * For random access iterators, this uses their @c + and @c - operations
+ * and are constant time. For other %iterator classes they are linear time.
+ */
+ template<typename _InputIterator>
+ inline typename iterator_traits<_InputIterator>::difference_type
+ distance(_InputIterator __first, _InputIterator __last)
+ {
+ // concept requirements -- taken care of in __distance
+ return __distance(__first, __last, __iterator_category(__first));
+ }
+
+ template<typename _InputIterator, typename _Distance>
+ inline void
+ __advance(_InputIterator& __i, _Distance __n, input_iterator_tag)
+ {
+ // concept requirements
+ __glibcpp_function_requires(_InputIteratorConcept<_InputIterator>)
+ while (__n--) ++__i;
+ }
+
+ template<typename _BidirectionalIterator, typename _Distance>
+ inline void
+ __advance(_BidirectionalIterator& __i, _Distance __n,
+ bidirectional_iterator_tag)
+ {
+ // concept requirements
+ __glibcpp_function_requires(_BidirectionalIteratorConcept<_BidirectionalIterator>)
+
+ if (__n > 0)
+ while (__n--) ++__i;
+ else
+ while (__n++) --__i;
+ }
+
+ template<typename _RandomAccessIterator, typename _Distance>
+ inline void
+ __advance(_RandomAccessIterator& __i, _Distance __n,
+ random_access_iterator_tag)
+ {
+ // concept requirements
+ __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>)
+ __i += __n;
+ }
+
+ /**
+ * @brief A generalization of pointer arithmetic.
+ * @param i An input iterator.
+ * @param n The "delta" by which to change @p i.
+ * @return Nothing.
+ *
+ * This increments @p i by @p n. For bidirectional and random access
+ * iterators, @p n may be negative, in which case @p i is decremented.
+ *
+ * For random access iterators, this uses their @c + and @c - operations
+ * and are constant time. For other %iterator classes they are linear time.
+ */
+ template<typename _InputIterator, typename _Distance>
+ inline void
+ advance(_InputIterator& __i, _Distance __n)
+ {
+ // concept requirements -- taken care of in __advance
+ __advance(__i, __n, __iterator_category(__i));
+ }
} // namespace std
-#endif /* __SGI_STL_INTERNAL_ITERATOR_BASE_FUNCS_H */
-
-
-// Local Variables:
-// mode:C++
-// End:
+#endif /* __GLIBCPP_INTERNAL_ITERATOR_BASE_FUNCS_H */
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