C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  private static member access by a friend class          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Anjo Gasa Guest Posted: Mon Feb 27, 2006 6:06 pm    Post subject: private static member access by a friend class I have two classes: // B.h class B { friend class A; //... private: static float rate; } // A.h class A { //... bool Init(); //... } // A.cpp bool A:Init() { //... B:rate = 5.0; } A.cpp comiles fine, I get an error with the linker: error LNK2001: unresolved external symbol "private: static float rate" Now, I've tried to find something related to this situation via Google and I'm rifling through TC++PL, and have yet to find anything that can explain why there is a linking error. Anjo Back to top Rolf Magnus Guest Posted: Mon Feb 27, 2006 6:06 pm    Post subject: Re: private static member access by a friend class Anjo Gasa wrote: Quote: I have two classes: // B.h class B { friend class A; //... private: static float rate; } // A.h class A { //... bool Init(); //... } // A.cpp bool A:Init() { //... B:rate = 5.0; } A.cpp comiles fine, That's strange. Your code contains several errors. Quote: I get an error with the linker: error LNK2001: unresolved external symbol "private: static float rate" You only declared B::rate, but never defined it. Quote: Now, I've tried to find something related to this situation via Google and I'm rifling through TC++PL, and have yet to find anything that can explain why there is a linking error. Look for "static member" in the index of your TC++PL. Back to top Victor Bazarov Guest Posted: Mon Feb 27, 2006 6:06 pm    Post subject: Re: private static member access by a friend class Anjo Gasa wrote: Quote: I have two classes: // B.h class B { friend class A; //... private: static float rate; That's a declaration. Where is it defined? Quote: } ; // A.h class A { //... bool Init(); //... } ; // A.cpp bool A:Init() { //... B:rate = 5.0; B::rate = 5.0f; Quote: } ; A.cpp comiles fine, I get an error with the linker: error LNK2001: unresolved external symbol "private: static float rate" Of course. You didn't define 'B::rate'. Read your favourite C++ book about static data members, especially the part about how they need to be defined somewhere. Quote: Now, I've tried to find something related to this situation via Google and I'm rifling through TC++PL, and have yet to find anything that can explain why there is a linking error. Well, now you know. V -- Please remove capital As from my address when replying by mail 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.