From -6142598476050600231 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,f5d433881cc29cff X-Google-Attributes: gidf78e5,public From: bparker@gil.com.au (Brian Parker) Subject: Re: Named return value optimisation- reprise. Date: 1997/06/24 Message-ID: <33af2d84.11809049@news.ipswich.gil.com.au>#1/1 X-Deja-AN: 252167549 References: <33a345bf.7425526@news.ipswich.gil.com.au> <5o7lbs$3a6@mulga.cs.mu.OZ.AU> <01bc7bf8$bb2c9be0$a56dadce@azguard> <33a885f3.6004413@news.ipswich.gil.com.au> <5oet82$b5g@tools.bbnplanet.com> X-Original-Date: Tue, 24 Jun 1997 03:34:53 GMT Organization: Global Info-Links News Server X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBFAgUBM69Q/OEDnX0m9pzZAQHE9AGAjmYDh25SmUzomt9QjudNRffhZTrhCYB9 Te+gGCZp/n8u2rBZb/yYV6Rw9jk7XxQY =xCJm Newsgroups: comp.std.c++ Originator: fjh@mundook.cs.mu.OZ.AU On 23 Jun 1997 13:42:59 PDT, Barry Margolin wrote: >In article <33a885f3.6004413@news.ipswich.gil.com.au>, >Brian Parker wrote: >>Actually, it's not even absolutely clear in the case of objects about >>to go out of scope- in a garbage-collected implementation memory can >>be retained beyond the local scope (or, as in the MV++ example, some >>of the object's memory may be statically allocated). > >Even in a GC'ed implementation, you can't refer to automatic objects once >the block they were allocated in has exited. GC permits an implementation >to reclaim memory once it has determined that it can't be accessed, but >doesn't require it to retain memory after an object has been declared >inaccessible (either by going out of scope or by an explicit call to free() >or delete). While it's possible for an implementation to make the explicit >action no-ops, and use GC for all reclamation (a la Lisp), as far as the >language semantics are concerned this lazy reclamation doesn't exist. I was unclear in my original posting- what I meant to say was that the internal dynamically-allocated memory of local objects could be retained by a GC, not that the automatic object itself was affected by the garbage collector (also note that I am not particularly defending that as a good design- I'm just pointing out that that it can happen). ,Brian Parker (bparker@gil.com.au) --- [ comp.std.c++ is moderated. To submit articles: try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ FAQ: http://reality.sgi.com/employees/austern_mti/std-c++/faq.html ] [ Policy: http://reality.sgi.com/employees/austern_mti/std-c++/policy.html ] [ Comments? mailto:std-c++-request@ncar.ucar.edu ]