wrote:
> I am confused at static variable in declaring and defining.
>
> I have the following code in header file,
>
> class c0;
>
> class c1 {
> static std::vector<c0> cs;
That's the declaration.
> };
>
> And in C file, I operate on c1::cs in some function. But VC7 compiler
> complains that c1::cs is not initialized.
>
> I have to add the following line to the top of the C code,
> std::vector<c0> c1::cs;
That's the definition.
> Then it works.
>
> This makes half sense to me. Static variable must be defined in
> addition to declaring.
Static member variables must. And only if they are of non-integral type
and are used outside the class itself.
> But how come the above newly statement does the
> definition?
Because it's outside of the class, at the namespace level.
> Is that because std::vector does some dummy
> initialization?
Nope. It's because the rules require it.
> Then I have another header file,
> class MyString {...};
>
> static MyString myStr; // This variable does not belong to any
> class
Then it's not a _member_, is it?
> Then in the C file when I have
> myStr = "";
> The compiler complains that I am re-defining myStr.
Huh? You must be including the header in more than one translation unit
and that introduces multiple _definitions_ in your program.
> I wonder what is going on? Because myStr is a standalone variable, so
> its definition is defferent from class member?
Yep. You got it!
V
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