Trent Mick <trentm@activestate.com>: The common technique for printing out a pointer has been to cast to a long and use the "%lx" printf modifier. This is incorrect on Win64 where casting to a long truncates the pointer. The "%p" formatter should be used instead. The problem as stated by Tim: > Unfortunately, the C committee refused to define what %p conversion "looks > like" -- they explicitly allowed it to be implementation-defined. Older > versions of Microsoft C even stuck a colon in the middle of the address (in > the days of segment+offset addressing)! The result is that the hex value of a pointer will maybe/maybe not have a 0x prepended to it. Notes on the patch: There are two main classes of changes: - in the various repr() functions that print out pointers - debugging printf's in the various thread_*.h files (these are why the patch is large) Closes SourceForge patch #100505.

--- a/Objects/methodobject.c	Fri Jun 30 14:58:20 2000 +0000
+++ b/Objects/methodobject.c	Fri Jun 30 15:01:00 2000 +0000
@@ -148,9 +148,9 @@
 		sprintf(buf, "<built-in function %.80s>", m->m_ml->ml_name);
 	else
 		sprintf(buf,
-			"<built-in method %.80s of %.80s object at %lx>",
+			"<built-in method %.80s of %.80s object at %p>",
 			m->m_ml->ml_name, m->m_self->ob_type->tp_name,
-			(long)m->m_self);
+			m->m_self);
 	return PyString_FromString(buf);
 }