2005-09-12 Chris Jefferson <chris@bubblescope.net>

	* include/bits/stl_algo.h (search_n): Delegate to specializations.
	(search_n(,,,,binary_predicate)): Likewise.
        (__search_n(forward_iterator_tag)): Original search_n, tweak to
        remove an unnecessary comparison.
        (__search_n(,,,,binary_predicate,forward_iterator_tag)): Likewise.

2005-09-12  Jim Xochellis  <jimxoch@yahoo.gr>

        * include/bits/stl_algo.h (__search_n(std::random_access_iterator_tag)):
	Add specialization.
        (__search_n(,,,,binary_predicate,std::random_access_iterator_tag)):
        Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@104192 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 4c8db92..154e32a 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,18 @@
+2005-09-12  Chris Jefferson  <chris@bubblescope.net>
+
+       * include/bits/stl_algo.h (search_n): Delegate to specializations.
+       (search_n(,,,,binary_predicate)): Likewise.
+       (__search_n(forward_iterator_tag)): Original search_n, tweak to
+       remove an unnecessary comparison.
+       (__search_n(,,,,binary_predicate,forward_iterator_tag)): Likewise.
+
+2005-09-12  Jim Xochellis  <jimxoch@yahoo.gr>
+
+       * include/bits/stl_algo.h (__search_n(std::random_access_iterator_tag)):
+       Add specialization.
+       (__search_n(,,,,binary_predicate,std::random_access_iterator_tag)):
+       Likewise.
+
 2005-09-12  Benjamin Kosnik  <bkoz@redhat.com>
 
        PR libstdc++/23417

diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index 5754d04..1a7fd6e 100644 (file)
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -607,6 +607,92 @@ namespace std
     }
 
   /**
+   *  @if maint
+   *  This is an uglified
+   *  search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&)
+   *  overloaded for forward iterators.
+   *  @endif
+  */
+  template<typename _ForwardIterator, typename _Integer, typename _Tp>
+    _ForwardIterator
+    __search_n(_ForwardIterator __first, _ForwardIterator __last,
+              _Integer __count, const _Tp& __val,
+              std::forward_iterator_tag)
+    {
+      __first = std::find(__first, __last, __val);
+      while (__first != __last)
+       {
+         typename iterator_traits<_ForwardIterator>::difference_type
+           __n = __count;
+         _ForwardIterator __i = __first;
+         ++__i;
+         while (__i != __last && __n != 1 && *__i == __val)
+           {
+             ++__i;
+             --__n;
+           }
+         if (__n == 1)
+           return __first;
+         if (__i == __last)
+           return __last;
+         __first = std::find(++__i, __last, __val);
+       }
+      return __last;
+    }
+
+  /**
+   *  @if maint
+   *  This is an uglified
+   *  search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&)
+   *  overloaded for random access iterators.
+   *  @endif
+  */
+  template<typename _RandomAccessIter, typename _Integer, typename _Tp>
+    _RandomAccessIter
+    __search_n(_RandomAccessIter __first, _RandomAccessIter __last,
+              _Integer __count, const _Tp& __val, 
+              std::random_access_iterator_tag)
+    {
+      
+      typedef typename std::iterator_traits<_RandomAccessIter>::difference_type
+       _DistanceType;
+
+      _DistanceType __tailSize = __last - __first;
+      const _DistanceType __pattSize = __count;
+
+      if (__tailSize < __pattSize)
+        return __last;
+
+      const _DistanceType __skipOffset = __pattSize - 1;
+      _RandomAccessIter __lookAhead = __first + __skipOffset;
+      __tailSize -= __pattSize;
+
+      while (1) // the main loop...
+       {
+         // __lookAhead here is always pointing to the last element of next 
+         // possible match.
+         while (!(*__lookAhead == __val)) // the skip loop...
+           {
+             if (__tailSize < __pattSize)
+               return __last;  // Failure
+             __lookAhead += __pattSize;
+             __tailSize -= __pattSize;
+           }
+         _DistanceType __remainder = __skipOffset;
+         for (_RandomAccessIter __backTrack = __lookAhead - 1; 
+              *__backTrack == __val; --__backTrack)
+           {
+             if (--__remainder == 0)
+               return (__lookAhead - __skipOffset); // Success
+           }
+         if (__remainder > __tailSize)
+           return __last; // Failure
+         __lookAhead += __remainder;
+         __tailSize -= __remainder;
+       }
+    }
+
+  /**
    *  @brief Search a sequence for a number of consecutive values.
    *  @param  first  A forward iterator.
    *  @param  last   A forward iterator.
@@ -632,26 +718,103 @@ namespace std
 
       if (__count <= 0)
        return __first;
-      else
+      if (__count == 1)
+       return std::find(__first, __last, __val);
+      return std::__search_n(__first, __last, __count, __val,
+                            std::__iterator_category(__first));
+    }
+
+  /**
+   *  @if maint
+   *  This is an uglified
+   *  search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&,
+   *          _BinaryPredicate)
+   *  overloaded for forward iterators.
+   *  @endif
+  */
+  template<typename _ForwardIterator, typename _Integer, typename _Tp,
+           typename _BinaryPredicate>
+    _ForwardIterator
+    __search_n(_ForwardIterator __first, _ForwardIterator __last,
+              _Integer __count, const _Tp& __val,
+              _BinaryPredicate __binary_pred, std::forward_iterator_tag)
+    {
+      while (__first != __last && !__binary_pred(*__first, __val))
+        ++__first;
+
+      while (__first != __last)
        {
-         __first = std::find(__first, __last, __val);
-         while (__first != __last)
+         typename iterator_traits<_ForwardIterator>::difference_type
+           __n = __count;
+         _ForwardIterator __i = __first;
+         ++__i;
+         while (__i != __last && __n != 1 && *__i == __val)
            {
-             typename iterator_traits<_ForwardIterator>::difference_type
-               __n = __count;
-             _ForwardIterator __i = __first;
              ++__i;
-             while (__i != __last && __n != 1 && *__i == __val)
-               {
-                 ++__i;
-                 --__n;
-               }
-             if (__n == 1)
-               return __first;
-             else
-               __first = std::find(__i, __last, __val);
+             --__n;
            }
-         return __last;
+         if (__n == 1)
+           return __first;
+         if (__i == __last)
+           return __last;
+         __first = ++__i;
+         while (__first != __last && !__binary_pred(*__first, __val))
+           ++__first;
+       }
+      return __last;
+    }
+
+  /**
+   *  @if maint
+   *  This is an uglified
+   *  search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&,
+   *          _BinaryPredicate)
+   *  overloaded for random access iterators.
+   *  @endif
+  */
+  template<typename _RandomAccessIter, typename _Integer, typename _Tp,
+          typename _BinaryPredicate>
+    _RandomAccessIter
+    __search_n(_RandomAccessIter __first, _RandomAccessIter __last,
+              _Integer __count, const _Tp& __val,
+              _BinaryPredicate __binary_pred, std::random_access_iterator_tag)
+    {
+      
+      typedef typename std::iterator_traits<_RandomAccessIter>::difference_type
+       _DistanceType;
+
+      _DistanceType __tailSize = __last - __first;
+      const _DistanceType __pattSize = __count;
+
+      if (__tailSize < __pattSize)
+        return __last;
+
+      const _DistanceType __skipOffset = __pattSize - 1;
+      _RandomAccessIter __lookAhead = __first + __skipOffset;
+      __tailSize -= __pattSize;
+
+      while (1) // the main loop...
+       {
+         // __lookAhead here is always pointing to the last element of next 
+         // possible match.
+         while (!__binary_pred(*__lookAhead, __val)) // the skip loop...
+           {
+             if (__tailSize < __pattSize)
+               return __last;  // Failure
+             __lookAhead += __pattSize;
+             __tailSize -= __pattSize;
+           }
+         _DistanceType __remainder = __skipOffset;
+         for (_RandomAccessIter __backTrack = __lookAhead - 1; 
+              __binary_pred(*__backTrack, __val); --__backTrack)
+           {
+             if (--__remainder == 0)
+               return (__lookAhead - __skipOffset); // Success
+           }
+         if (__remainder > __tailSize)
+           return __last; // Failure
+         __lookAhead += __remainder;
+         __tailSize -= __remainder;
        }
     }
 
@@ -685,40 +848,14 @@ namespace std
 
       if (__count <= 0)
        return __first;
-      else
+      if (__count == 1)
        {
-         while (__first != __last)
-           {
-             if (__binary_pred(*__first, __val))
-               break;
-             ++__first;
-           }
-         while (__first != __last)
-           {
-             typename iterator_traits<_ForwardIterator>::difference_type
-               __n = __count;
-             _ForwardIterator __i = __first;
-             ++__i;
-             while (__i != __last && __n != 1 && __binary_pred(*__i, __val))
-               {
-                 ++__i;
-                 --__n;
-               }
-             if (__n == 1)
-               return __first;
-             else
-               {
-                 while (__i != __last)
-                   {
-                     if (__binary_pred(*__i, __val))
-                       break;
-                     ++__i;
-                   }
-                 __first = __i;
-               }
-           }
-         return __last;
+         while (__first != __last && !__binary_pred(*__first, __val))
+           ++__first;
+         return __first;
        }
+      return std::__search_n(__first, __last, __count, __val, __binary_pred,
+                            std::__iterator_category(__first));
     }
 
   /**