Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!uunet!stan!garya
From: garya@Solbourne.COM (Gary Aitken)
Newsgroups: comp.windows.x
Subject: Re: Toolkit for Open Look *and* OSF/Motif Look and Feel
Message-ID: <1991Feb26.230024.22535@Solbourne.COM>
Date: 26 Feb 91 23:00:24 GMT
Organization: Solbourne Computer, Inc.
Lines: 29

> I put code in the new handler to free stuff up and signal an error?

That's the problem.  There is no way to signal an error in a C++ constructor
so that everything unwinds and the base class destructors properly get called
to free up their stuff.  In the future, when C++ does error/exception handling,
there may be a way to do this.

> How much of your code actually checks for the return value from oi_create
> and does something reasonable with it?  How often is that something
> more than mapping a (cached) window and saying, "Sorry, out of memory."?

Some, certainly not all.  However, forcing the pointer to NULL at the time of
failure, rather than returning a pointer to garbage in the free/possibly soon
to be allocated heap forces recognition of the error at a much earlier 
phase in the execution of the program -- essentially, the next time it is
used.  Not doing so could delay recognition of the problem until literaly
hours later, and it is potentially much harder to find; certainly much more
time consuming

> I'm not saying the oi_create stuff is wrong, but I'm not convinced it's
> worth the trouble.

Suit yourself.  You're free to call the constructor directly if you want.

-- 
Gary Aitken

Solbourne Computer Inc.    ARPA: garya@Solbourne.COM
Longmont, CO               UUCP: !{boulder,sun}!stan!garya