C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Template Parameter Friends          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message õá Guest Posted: Sun Apr 17, 2005 6:01 pm    Post subject: Template Parameter Friends I know it's nonstandard,but is there any possibility to declare a template parameter as a friend? It's an essential part of the "property" library,which is quite useful (unimportant for the answer). I have g++ 3.4.2 and neither of the following compiles: template <...> class field_get { #1 friend T; #2 friend class T; #3 struct friend_maker { typedef T T2; } typedef friend_maker::T2 friend_type; friend friend_type; }; Please, is there something I can do about this? [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Stefan Strasser Guest Posted: Sun Apr 17, 2005 9:09 pm    Post subject: Re: Template Parameter Friends õá schrieb: Quote: I know it's nonstandard,but is there any possibility to declare a template parameter as a friend? It's an essential part of the "property" library,which is quite useful (unimportant for the answer). what property library? Quote: Please, is there something I can do about this? template<typename T> struct befr{ typedef T type; }; template<typename T> struct A{ friend class befr<T>::type; }; [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Valentin Samko Guest Posted: Mon Apr 18, 2005 9:04 am    Post subject: Re: Template Parameter Friends õá wrote: Quote: I know it's nonstandard,but is there any possibility to declare a template parameter as a friend? It's an essential part of the "property" library,which is quite useful (unimportant for the answer). I have g++ 3.4.2 and neither of the following compiles: There is no universal solution, but there are a few compiler dependent hacks, see the CUJ article http://www.cuj.com/documents/s=8943/cujexp0312wilson2/ -- Valentin Samko http://val.samko.info [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ralph Zhang Guest Posted: Mon Apr 18, 2005 9:11 am    Post subject: Re: Template Parameter Friends Why can't it compile? in VC7.1 it compiles very well: template <typename T> class field_get { friend class T; }; [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top õá Guest Posted: Mon Apr 18, 2005 3:13 pm    Post subject: Re: Template Parameter Friends Thanks! I knew about the article,but forgot to try the templated version.Now it works. P.S.:By "property library" I mean the concepts from Wilsons book from "Imperfect C++",which is in one of his libraries. [ 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.