Path: utzoo!utgpu!watserv1!watmath!att!dptg!ulysses!andante!alice!ark
From: ark@alice.UUCP (Andrew Koenig)
Newsgroups: comp.lang.c++
Subject: Re: C++ coding standards (Comment needed)
Keywords: standard,variables
Message-ID: <11290@alice.UUCP>
Date: 5 Sep 90 02:48:05 GMT
References: <56642@microsoft.UUCP> <41673@think.Think.COM> <56953@microsoft.UUCP> <57167@microsoft.UUCP>
Organization: AT&T Bell Laboratories, Liberty Corner NJ
Lines: 23

In article <57167@microsoft.UUCP>, jimad@microsoft.UUCP (Jim ADCOCK) writes:

> |	func()
> |	{	{ int i; .... }
> |		{ int j; .... }
> |	}

> |i and j's live ranges do not overlap, so they can (and do with some compilers)
> |share the same storage location.

> Yes, but C++ defines that destruction of named objects be on exit from
> scope [with few exceptions], thus greatly restricting a compilers from
> performing these optimizations on other than primitives.

But in this example, the scopes of `i' and `j' end at the
close braces at the end of their respective lines.

Therefore a C++ implementation is certainly entitled to let
`i' and `j' share storage, as long as it destroys `i' before
constructing `j.'
-- 
				--Andrew Koenig
				  ark@europa.att.com