c++/1888: #if defined(xor) won't work

[moz@compsoc.man.ac.uk]

>Number:         1888
>Category:       c++
>Synopsis:       #if defined(xor) won't work
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Feb 06 04:26:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     John Levon
>Release:        gcc C++ > 2.95.2
>Organization:
>Environment:
Linux 2.4 (RedHat 7.0)
>Description:
In both RH gcc-2.96.69 and gcc snapshot 2001-02-20, the 
code :

#if defined(xor)
// blah
#endif

is not accepted, giving :

"defined" without an identifier

This is used in the Qt 1.45 headers for one.
>How-To-Repeat:
Attempt to compile the code snippet above :

g++ snippet.c
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: