diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 3dfa2c3b1474..742083107b00 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-09  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/bits/stl_tree.h (_Rb_tree<>::_M_const_cast_iter): Add
+	and use it throughout.
+
 2010-11-09  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR libstdc++/46385
diff --git a/libstdc++-v3/include/bits/stl_tree.h b/libstdc++-v3/include/bits/stl_tree.h
index b85398de3f3e..3ffd996ae93a 100644
--- a/libstdc++-v3/include/bits/stl_tree.h
+++ b/libstdc++-v3/include/bits/stl_tree.h
@@ -556,6 +556,11 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 
     private:
+      iterator
+      _M_const_cast_iter(const_iterator __cit)
+      { return iterator(static_cast<_Link_type>
+			(const_cast<_Base_ptr>(__cit._M_node))); }
+
       iterator
       _M_insert_(_Const_Base_ptr __x, _Const_Base_ptr __y,
 		 const value_type& __v);
@@ -719,8 +724,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 	const_iterator __result = __position;
 	++__result;
 	_M_erase_aux(__position);
-	return iterator(static_cast<_Link_type>
-			(const_cast<_Base_ptr>(__result._M_node)));
+	return _M_const_cast_iter(__result);
       }
 #else
       void
@@ -737,8 +741,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       erase(const_iterator __first, const_iterator __last)
       {
 	_M_erase_aux(__first, __last);
-	return iterator(static_cast<_Link_type>
-			(const_cast<_Base_ptr>(__last._M_node)));
+	return _M_const_cast_iter(__last);
       }
 #else
       void
@@ -1279,8 +1282,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 	}
       else
 	// Equivalent keys.
-	return iterator(static_cast<_Link_type>
-			(const_cast<_Base_ptr>(__position._M_node)));
+	return _M_const_cast_iter(__position);
     }
 
   template<typename _Key, typename _Val, typename _KeyOfValue,