Error C2491 Definition Of Dllimport Static Data Member
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Error C2491 Definition Of Dllimport Function Not Allowed
Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow definition of dllimport static data member not allowed qt Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each cannot define dllimport entity other. Join them; it only takes a minute: Sign up C++ definition of dllimport static data member up vote 14 down vote favorite 4 I do have a class which looks like below: //.h file class __declspec(dllimport) MyClass { public: //stuff private: static int myInt; }; // .cpp file int MyClass::myInt = 0; I get the following compile error:
A Function Declared Dllimport May Not Be Defined
error C2491: 'MyClass::myInt' : definition of dllimport static data member not allowed what should I do? c++ dll static static-members share|improve this question asked Aug 16 '10 at 9:34 MBZ 5,6301767133 add a comment| 3 Answers 3 active oldest votes up vote 19 down vote accepted __declspec(dllimport) means that the current code is using the DLL that implements your class. The member functions and static data members are thus defined in the DLL, and defining them again in your program is an error. If you are trying to write the code for the DLL that implements this class (and thus defines the member functions and static data members) then you need to mark the class __declspec(dllexport) instead. It is common to use a macro for this. When building your DLL you define a macro BUILDING_MYDLL or similar. In your header for MyClass you then have: #ifdef BUILDING_MYDLL #define MYCLASS_DECLSPEC __declspec(dllexport) #else #define MYCLASS_DECLSPEC __declspec(dllimport) #endif class MYCLASS_DECLSPEC MyClass { ... }; This means that you can share the header between the DLL
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C4273
community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up inconsistent dll linkage & definition of dllimport static data member not allowed up vote 2 http://stackoverflow.com/questions/3491990/c-definition-of-dllimport-static-data-member down vote favorite Assuming I have these two files: Header.h class DLL ExportClass{ public: ExportClass(); static int test; }; Source.cpp #ifdef EXPORT #define DLL __declspec(dllexport) #else #define DLL __declspec(dllimport) #endif #include "Header.h" int ExportClass::test = 0; ExportClass::ExportClass(){ } And I won't define EXPORT (to import a already exported class with a static member), why do I get these warnings: 1>source.cpp(11): warning C4273: 'test' : inconsistent dll linkage 1> header.h(4) : see http://stackoverflow.com/questions/19926736/inconsistent-dll-linkage-definition-of-dllimport-static-data-member-not-allowe previous definition of 'public: static int ExportClass::test' 1>source.cpp(13): warning C4273: 'ExportClass::ExportClass' : inconsistent dll linkage 1> header.h(3) : see previous definition of '{ctor}' And this error: 1>source.cpp(11): error C2491: 'ExportClass::test' : definition of dllimport static data member not allowed If I define EXPORT it works. I kind of understand the warnings, but I thought, that the static variable and the ctor could be ignored by the compiler, because the whole class is declared as __declspec(dllimport) anyway. I want to use the same codebase for the __declspec(dllexport) and __declspec(dllimport) - but it seems the compiler stll tries to define these symbols that are marked as __declspec(dllexport) in their declaration. What is the common practice to solve this problem? visual-c++ dllimport dllexport share|improve this question asked Nov 12 '13 at 10:32 Constantin 4,41084080 add a comment| 2 Answers 2 active oldest votes up vote 11 down vote accepted You are expecting the compiler to ignore a very serious mishap. It encountered the __declspec(dllimport) attribute on the class declaration, that quite unequivocally states that the class implementation is present in different module that's going to bound at runtime. But then it encountered the definition as well, completely unexpected since the attribute contract says that it is compiled in an entirely different project.
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C2491 definition of dllimport static data member not allowed Bindings to OpenAL Moderators: OGRE Team, OgreAL Moderators Post a reply 11 posts • Page 1 of 1 Reply with quote C2491 definition of dllimport static data member not allowed by Jekteir » Thu Jul 19, 2007 12:57 am Hi CaseyB, Many thanks for all your help with licensing/compilation issues so far. Annoyingly we had to move from Code::Blocks to VC++ 2005 due to various problems with all the tools, and are now getting to experience VC++'s unique pecadillos with the repository we had just about got working with C::B and MinGW GCC! In particular right now there are a couple of errors with OgreAL's SoundManager during compilation using VC++ 2005: >..\OgreAL\OgreALsrc\OgreALSoundManager.cpp(38) : error C2491: 'Ogre::Singleton