in which case, windows guarantee the static variable defined inside inline member functions are unique across modules(dll/exe)?

Question

According to this post: global variable not exported will be only visible to its own module.

I am wondering what is the story for static variables defined inside a inline member function of a class, for example:

//cat.h

#ifdef EXPORT_ADD_
#define DLL_ __declspec(dllexport)
#else
#define DLL_ __declspec(dllimport)
#endif

Class DLL_ Cat
{
public:
    static void foo()
    {
        static int i = 0;
        std::cout << i++ << std::endl;
    }
}

1) if cat.h is included in multiple module, say d1.dll, d2,dll and Cat::foo() are called in each module what result will be guarantee to be get?
2) it seems that __declspec(dllexport) and__declspec(dllimport) play a important role. In my test,

Class  Cat {...} //DLL_ is removed

or

#define DLL_ //__declspec(dllimport)  comment out dllimport

the static variable will not be unique

I am wondering what is the Rule of thumb to deal with static variable inside inline member functions. Thanks.

Simple rule: don't do it, you are looking at a huge mess if things go wrong. Just put it in the cpp — JVApen, Jul 25 '18 at 17:17
"in which case, windows guarantee" - Don't care about that. Care about what the C++ standard guarantees. — Jesper Juhl, Jul 25 '18 at 17:26
@JesperJuhl The C++ standard doesn't contemplate a concept of shared libraries, and says nothing about their behavior. The behavior at issue here is necessarily implementation-dependent. — Igor Tandetnik, Jul 25 '18 at 18:21

in which case, windows guarantee the static variable defined inside inline member functions are unique across modules(dll/exe)?

0 Answers0