Accessing static data members?

[GusBrown]

If I have a class.....

class cdcHolder
{
public:
cdcHolder();
virtual ~cdcHolder();

static CDC* cdcPointer;
};

And implementation.....

cdcHolder::cdcHolder() {}
cdcHolder::~cdcHolder() {}

Why, when I do the following in a seperate file, do I get this error message:

cdcHolder temp;
temp.cdcPointer = pDC; // pDC is of type CDC*

error LNK2001: unresolved external symbol "public: static class CDC * cdcHolder::cdcPointer" (?cdcPointer@cdcHolder@@2PAVCDC@@A)

I don't get it. I'm not trying to do something really stupid am I? All I want is to set a static member variable and it's driving me crazy!

Any help VERY much appreciated,

Gus

 

[GusBrown]

Perhaps to simply things - I get exactly the same error trying to compile:

// start of CRectangle.cpp
class CRectangle {
public:
static int staticInt;
CRectangle ();
};

CRectangle::CRectangle () {}

void main () {
CRectangle cR;
cR.staticInt = 1; // this line causes the error
}
// end of CRectangle.cpp