stl_tree.h (_Rb_tree<>::erase(const _Key&)): Don't call std::distance unnecessarily.

2006-10-07  Ion Gaztanaga  <igaztanaga@gmail.com>
	    Paolo Carlini  <pcarlini@suse.de>

	* include/bits/stl_tree.h (_Rb_tree<>::erase(const _Key&)): Don't
	call std::distance unnecessarily.

Co-Authored-By: Paolo Carlini <pcarlini@suse.de>

From-SVN: r117529

libstdc++-v3/ChangeLog

+2006-10-07  Ion Gaztanaga  <igaztanaga@gmail.com>
+	    Paolo Carlini  <pcarlini@suse.de>
+
+	* include/bits/stl_tree.h (_Rb_tree<>::erase(const _Key&)): Don't
+	call std::distance unnecessarily.
+
 2006-10-06  Paolo Carlini  <pcarlini@suse.de>
 
 	PR libstdc++/29368

libstdc++-v3/include/bits/stl_tree.h

@@ -1269,10 +1269,10 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::
     erase(const _Key& __x)
     {
-      pair<iterator,iterator> __p = equal_range(__x);
-      size_type __n = std::distance(__p.first, __p.second);
+      pair<iterator, iterator> __p = equal_range(__x);
+      const size_type __old_size = size();
       erase(__p.first, __p.second);
-      return __n;
+      return __old_size - size();
     }
 
   template<typename _Key, typename _Val, typename _KoV,