This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: debug safe iterator patch

Attached patch applied

2012-02-06 François Dumont <>

        * include/debug/safe_iterator.h
        (_Safe_iterator::_M_before_dereferenceable): Avoid the expensive
        creation of a _Safe_iterator instance to do the check.


On 02/05/2012 06:30 PM, Paolo Carlini wrote:
On 02/05/2012 06:29 PM, François Dumont wrote:

Here is a small performance patch for the debug mode. Nothing urgent, just tell me if I can apply it on trunk at the moment.
It impacts only debug-mode, thus it's pretty safe. If you tested it check-debug I guess you can commit it to mainline even now.


Index: include/debug/safe_iterator.h
--- include/debug/safe_iterator.h	(revision 183913)
+++ include/debug/safe_iterator.h	(working copy)
@@ -380,8 +380,12 @@
       _M_before_dereferenceable() const
-	_Self __it = *this;
-	return __it._M_incrementable() && (++__it)._M_dereferenceable();
+	if (this->_M_incrementable())
+	{
+	  _Iterator __base = base();
+	  return ++__base != _M_get_sequence()->_M_base().end();
+	}
+	return false;
       /// Is the iterator incrementable?

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]