C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  using declaration question          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Christopher Benson-Manica Guest Posted: Thu Feb 26, 2004 7:48 pm    Post subject: using declaration question Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; ? -- Christopher Benson-Manica | I *should* know what I'm talking about - if I ataru(at)cyberspace.org | don't, I need to know. Flames welcome. Back to top Jonathan Turkanis Guest Posted: Thu Feb 26, 2004 8:15 pm    Post subject: Re: using declaration question "Christopher Benson-Manica" <ataru (AT) nospam (DOT) cyberspace.org> wrote in message news:c1lihi$504$1 (AT) chessie (DOT) cirr.com... Quote: Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; Interesting question! It seems to be allowed by the grammar; it may be illegal for some other reason, however. VC7.1 is the only compiler I've tried which accepts it. Jonathan Back to top Pete Becker Guest Posted: Thu Feb 26, 2004 8:19 pm    Post subject: Re: using declaration question Christopher Benson-Manica wrote: Quote: Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; Because destructors, like constructors, do not have names, and a using declaration requires a name. -- Pete Becker Dinkumware, Ltd. (http://www.dinkumware.com) Back to top Mike Wahler Guest Posted: Thu Feb 26, 2004 8:24 pm    Post subject: Re: using declaration question "Christopher Benson-Manica" <ataru (AT) nospam (DOT) cyberspace.org> wrote Quote: Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; ==================================================================== ISO/IEC 14882:1998(E) 7.3.3 The using declaration 4 A using­-declaration used as a member­-declaration shall refer to a member of a base class of the class being defined, shall refer to a member of an anonymous union that is a member of a base class of the class being defined, or shall refer to an enumerator for an enumeration type that is a member of a base class of the class being defined. [Example: class C { int g(); }; class D2 : public B { using B::f; // OK: B is a base of D2 using B::e; // OK: e is an enumerator of base B using B:; // OK: x is a union member of base B using C::g; // error: C isn’t a base of D2 }; --end example] [Note: since constructors and destructors do not have names, a using­-declaration cannot refer to a constructor <<===== or a destructor for a base class. Since specializations of member templates for conversion functions are not found by name lookup, they are not considered when a using­-declaration specifies a conversion function (14.5.2). ] If an assignment operator brought from a base class into a derived class scope has the signature of a copy­-assignment operator for the derived class (12., the using­- declaration does not by itself suppress the implicit declaration of the derived class copy­-assignment operator; the copy­-assignment operator from the base class is hidden or overridden by the implicitly­-declared copy­-assignment operator of the derived class, as described below. ==================================================================== -Mike Back to top Mike Wahler Guest Posted: Thu Feb 26, 2004 8:25 pm    Post subject: Re: using declaration question "Jonathan Turkanis" <technews (AT) kangaroologic (DOT) com> wrote Quote: "Christopher Benson-Manica" <ataru (AT) nospam (DOT) cyberspace.org> wrote in message news:c1lihi$504$1 (AT) chessie (DOT) cirr.com... Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; Interesting question! It seems to be allowed by the grammar; it may be illegal for some other reason, however. Yes, see 7.3.3.4 Quote: VC7.1 is the only compiler I've tried which accepts it. Baaad Microsoft! :-) -Mike Back to top Jonathan Turkanis Guest Posted: Thu Feb 26, 2004 8:30 pm    Post subject: Re: using declaration question "Mike Wahler" <mkwahler (AT) mkwahler (DOT) net> wrote Quote: "Jonathan Turkanis" <technews (AT) kangaroologic (DOT) com> wrote in message news:c1lk2v$1jg271$1 (AT) ID-216073 (DOT) news.uni-berlin.de... "Christopher Benson-Manica" <ataru (AT) nospam (DOT) cyberspace.org> wrote in message news:c1lihi$504$1 (AT) chessie (DOT) cirr.com... Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; Interesting question! It seems to be allowed by the grammar; it may be illegal for some other reason, however. Yes, see 7.3.3.4 That'll teach me to skip over notes! Jonathan Back to top Christopher Benson-Manica Guest Posted: Thu Feb 26, 2004 8:44 pm    Post subject: Re: using declaration question Mike Wahler <mkwahler (AT) mkwahler (DOT) net> spoke thus: Quote: 7.3.3 The using declaration snip lovely quote from Standard Ah, a quote from the Standard - thank you (even though it has now obliterated all my hopes and dreams...) So here's my SUPER question: How can I reconcile conflicting destructor declarations when multiply inheriting, which I WOULD do with using; if that old wolf Stroustrup hadn't forbidden it...? *sigh* -- Christopher Benson-Manica | I *should* know what I'm talking about - if I ataru(at)cyberspace.org | don't, I need to know. Flames welcome. Back to top Mike Wahler Guest Posted: Thu Feb 26, 2004 9:10 pm    Post subject: Re: using declaration question "Christopher Benson-Manica" <ataru (AT) nospam (DOT) cyberspace.org> wrote Quote: Mike Wahler <mkwahler (AT) mkwahler (DOT) net> spoke thus: 7.3.3 The using declaration snip lovely quote from Standard Ah, a quote from the Standard - thank you (even though it has now obliterated all my hopes and dreams...) Please don't shoot the messenger. :-) Quote: So here's my SUPER question: How can I reconcile conflicting destructor declarations when multiply inheriting, which I WOULD do with using; if that old wolf Stroustrup hadn't forbidden it...? *sigh* Sorry, I'm a MI 'virgin', hopefully one of the gurus can help. I am watching your little 'project' with interest. Have you visited Dietmar's web site? -Mike Back to top Jonathan Turkanis Guest Posted: Thu Feb 26, 2004 9:20 pm    Post subject: Re: using declaration question "Christopher Benson-Manica" <ataru (AT) nospam (DOT) cyberspace.org> wrote in message news:c1llrj$622$1 (AT) chessie (DOT) cirr.com... Quote: Mike Wahler <mkwahler (AT) mkwahler (DOT) net> spoke thus: Ah, a quote from the Standard - thank you (even though it has now obliterated all my hopes and dreams...) So here's my SUPER question: How can I reconcile conflicting destructor declarations when multiply inheriting, which I WOULD do with using; if that old wolf Stroustrup hadn't forbidden it...? *sigh* If you're not planning on calling the destructors explicitly, you don't need to reconcile them. If you want to call one explicitly, you can qualify it with its namespace or enclosing class. What are you trying to do? Jonathan Back to top Christopher Benson-Manica Guest Posted: Thu Feb 26, 2004 9:55 pm    Post subject: Re: using declaration question Jonathan Turkanis <technews (AT) kangaroologic (DOT) com> spoke thus: Quote: If you're not planning on calling the destructors explicitly, you don't need to reconcile them. Well, only one of them is virtual, so my compiler has been complaining... At any rate, there is *something* amiss, although it could be my fault ;) Quote: What are you trying to do? Not go insane... -- Christopher Benson-Manica | I *should* know what I'm talking about - if I ataru(at)cyberspace.org | don't, I need to know. Flames welcome. Back to top Ralf Schneewei? Guest Posted: Thu Feb 26, 2004 11:39 pm    Post subject: Re: using declaration question Christopher Benson-Manica <ataru (AT) nospam (DOT) cyberspace.org> wrote Quote: Why can't I use a class destructor in a using declaration: using MyClass::~MyClass; ? Because the child class has another name. The name of the destructor is always the name of the class. To build the call chain of destructors the compiler needs a destructor in the parent and the child class. Ralf www.oop-trainer.de Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ language (comp.lang.c++) All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.