Path: utzoo!attcan!uunet!microsoft!jimad
From: jimad@microsoft.UUCP (Jim ADCOCK)
Newsgroups: comp.lang.c++
Subject: Re: Declare at first use? (was Re: C++ coding standards)
Keywords: standard,variables
Message-ID: <56747@microsoft.UUCP>
Date: 20 Aug 90 18:57:51 GMT
References: <2161@runxtsa.runx.oz.au> <1990Aug13.182226.24141@alias.uucp> <56642@microsoft.UUCP> <1990Aug17.191939.3990@ingres.Ingres.COM>
Reply-To: jimad@microsoft.UUCP (Jim ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 22

In article <1990Aug17.191939.3990@ingres.Ingres.COM> jas@llama.Ingres.COM (Jim Shankland) writes:
|In article <56642@microsoft.UUCP> jimad@microsoft.UUCP (Jim ADCOCK) writes:
|>Hm, I'm not sure I understand what you're trying to say here.  In the 
|>following code:
|>
|>	for (int i=0; i<1000; ++i)
|>	{
|>		FOO foo(i);
|>		foo.DoSomething();
|>	}
|
|>It is certainly not the case that a thousand foos reside simultaneously
|>on the stack.
|
|Yes, but if you don't want foo's constructor and destructor to be called
|on each loop iteration, you probably want to declare foo outside the loop,
|even if it only gets used inside the body of the loop.

Yes, I agree.  My understanding is that foo can be used for the side-effects
of its constructor and destructor, so that the compiler does not even have
the option of moving foo outside the loop.  If you don't want 1000s of
construction/destructions, move foo outside the loop.