From -3893384593007836865 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,bda3b729e5d0c564 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 1993-04-06 13:13:18 PST Newsgroups: comp.std.c++ Path: gmd.de!newsserver.jvnc.net!howland.reston.ans.net!usc!sdd.hp.com!network.ucsd.edu!munnari.oz.au!metro!news From: maxtal@physics.su.OZ.AU (John Max Skaller) Subject: Re: Guaranteed order of destruction for auto objects? Message-ID: <1993Apr6.185713.18835@ucc.su.OZ.AU> Sender: news@ucc.su.OZ.AU Nntp-Posting-Host: physics.su.oz.au Organization: School of Physics, University of Sydney, Australia References: <25207@alice.att.com> <25220@alice.att.com> Date: Tue, 6 Apr 1993 18:57:13 GMT Lines: 47 > > FooBar() > > { > > goto A ; > > B : > > Foo a ; > > goto C ; > > A : > > Bar b ; > > goto B ; > > C : > > // ... > > } > > > > (Note that b gets constructed before a.) > > > > Or is this forbidden by the rule about jumping over an initializer? > >It is indeed not allowed to jump past an initializer (except of course if >the initializer is in an inner scope that is completely bypassed by the >jump). > Is there a rule about CALLING past an initialiser? This came up when I was considering nested functions. If there are forward declarations, it is possible for a nested function to reference an uninitialised variable. Well, while trying to work out sensible rules that would prevent this, it occured to me the problem ALREADY exists anyhow for non-nested functions: extern T g(); T x=g(); // does a 'goto' that skips past an initialisation T y=k(); T g() { return y;} The second question is whether this rule (or no rule :-) is acceptable for nested functions. -- JOHN (MAX) SKALLER, INTERNET:maxtal@suphys.physics.su.oz.au Maxtal Pty Ltd, CSERVE:10236.1703 6 MacKay St ASHFIELD, Mem: SA IT/9/22,SC22/WG21 NSW 2131, AUSTRALIA