C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Reference to a forward declared class as class member?          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message Stephan Br?nnimann Guest Posted: Fri Nov 19, 2004 3:07 pm    Post subject: Reference to a forward declared class as class member? Dear all is the definition of Foo::bar_, which is a reference to a forward declared class, well defined according to the standard? My gut feel tells me that it's not and that it works in g++ by accident only. foo.h ===== class Bar; // in bar.h class Foo { public: Foo(Bar& bar); private: Foo& operator=(const Foo&); // not implemented private: Bar& bar_; }; foo.cc ====== #include "bar.h" Foo::Foo(Bar& bar) : bar_(bar) { // empty } Stephan Brönnimann [email]broeni (AT) osb-systems (DOT) com[/email] Open source rating and billing engine for communication networks. P.S. I know I can use a pointer to Bar instead. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Victor Bazarov Guest Posted: Sat Nov 20, 2004 10:36 am    Post subject: Re: Reference to a forward declared class as class member? Stephan Br?nnimann wrote: Quote: Dear all is the definition of Foo::bar_, which is a reference to a forward declared class, well defined according to the standard? Yes. Quote: My gut feel tells me that it's not and that it works in g++ by accident only. I wish I had accidents like that more... Quote: [...] V [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Bob Hairgrove Guest Posted: Sat Nov 20, 2004 6:19 pm    Post subject: Re: Reference to a forward declared class as class member? On 19 Nov 2004 10:07:39 -0500, [email]broeni (AT) hotmail (DOT) com[/email] (Stephan Br?nnimann) wrote: Quote: Dear all is the definition of Foo::bar_, which is a reference to a forward declared class, well defined according to the standard? My gut feel tells me that it's not and that it works in g++ by accident only. foo.h ===== class Bar; // in bar.h class Foo { public: Foo(Bar& bar); private: Foo& operator=(const Foo&); // not implemented private: Bar& bar_; }; foo.cc ====== #include "bar.h" Foo::Foo(Bar& bar) : bar_(bar) { // empty } It is legal AFAICS. See the last example given in section 9.1.2 of the standard, which uses references to forward-declared, but not defined, classes. -- Bob Hairgrove [email]NoSpamPlease (AT) Home (DOT) com[/email] [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] 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 (Moderated) 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.