C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  static data member          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Guest Posted: Thu Jan 29, 2004 3:13 pm    Post subject: static data member what is meaning of this? (MS VC++ .NET) ---------------------- Linking... machine.obj : error LNK2001: unresolved external symbol "private: static class std::vector<struct GessoidMachine::Resolution,class std::allocator GessoidMachine::Machine::resolution" (?resolution@Machine@GessoidMachine@@0V?$vector@UResolution@GessoidMachine@@V?$allocator@UResolution@GessoidMachine@@@std@@@std@@A) machine.obj : error LNK2001: unresolved external symbol "private: static struct SDL_Surface * GessoidMachine::Machine::screen" (?screen@Machine@GessoidMachine@@0PAUSDL_Surface@@A) machine.obj : error LNK2001: unresolved external symbol "private: static int GessoidMachine::Machine::resolution_index" (?resolution_index@Machine@GessoidMachine@@0HA) ..Debug/main.exe : fatal error LNK1120: 3 unresolved externals ---------------------- The error is in this code: (All member functions & data are static because I want only one instance of "Machine" in my project and I want access in any data member without this-> ---------------------- class Machine { public: static member1(arg1, arg2); static member2(); ....... private: // handle all resolutions supported from system static vector <Resolution> resolution; static int resolution_index; static SDL_Surface *screen; }; ---------------------- Back to top John Carson Guest Posted: Thu Jan 29, 2004 3:29 pm    Post subject: Re: static data member "<- Chameleon ->" <cham_gss (AT) hotmail (DOT) NOSPAM.com> wrote Quote: what is meaning of this? (MS VC++ .NET) ---------------------- Linking... machine.obj : error LNK2001: unresolved external symbol "private: static class std::vector<struct GessoidMachine::Resolution,class std::allocator GessoidMachine::Machine::resolution" (?resolution@Machine@GessoidMachine@@0V?$vector@UResolution@GessoidMachine@@ V?$allocator@UResolution@GessoidMachine@@@std@@@std@@A) Quote: machine.obj : error LNK2001: unresolved external symbol "private: static struct SDL_Surface * GessoidMachine::Machine::screen" (?screen@Machine@GessoidMachine@@0PAUSDL_Surface@@A) machine.obj : error LNK2001: unresolved external symbol "private: static int GessoidMachine::Machine::resolution_index" (?resolution_index@Machine@GessoidMachine@@0HA) .Debug/main.exe : fatal error LNK1120: 3 unresolved externals ---------------------- The error is in this code: (All member functions & data are static because I want only one instance of "Machine" in my project and I want access in any data member without this- ---------------------- class Machine { public: static member1(arg1, arg2); static member2(); ....... private: // handle all resolutions supported from system static vector static int resolution_index; static SDL_Surface *screen; }; ---------------------- static data members are like member functions: you declare them in the header file and then define them in the .cpp file. Basically, storage is allocated for ordinary data members when you define an object of the class. But static data members are independent of any class object and hence you need to define them separately in order for storage to be allocated for them. Thus your .cpp file needs to contain: vector <Resolution> Machine::resolution; int Machine::resolution_index; SDL_Surface *Machine::screen; Note that you must omit the static keyword in these definitions. -- John Carson 1. To reply to email address, remove donald 2. Don't reply to email address (post here instead) Back to top Guest Posted: Thu Jan 29, 2004 3:33 pm    Post subject: Re: static data member Aaaaaaaaa!!!!!! How much idiot I am? 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.