Hi.
I declare a singleton on a MFC extension DLL, like this:
<pre>
//header file: SingleTon.h
class AFX_EXT_CLASS CMySingleton
{
public:
static CMySingleton* Instance()
{
if(!singleton)
singleton = new CMySingleton();
return singleton;
}
int a;
// Other non-static member functions
private:
CMySingleton() {}; // Private
constructor
CMySingleton(const CMySingleton&); // Prevent copy-
construction
CMySingleton& operator=(const CMySingleton&); // Prevent
assignment
virtual ~CMySingleton() {};
static CMySingleton* singleton;
};
And in a cpp file I code the following line:
CMySingleton* CMySingleton::singleton = NULL;
</pre>
Code 2:
<pre>
CMySingleton *a;
a = CMySingleton::Instance();
</pre>
The problem is when I code "code 2" in a Regular Dll, all works fine,
but when I code "code 2" in another MFC extension DLL gives an error:
<pre>
unresolved external symbol "private: static class CMySingleton*
CMySingleton::singleton" (?singleton@CMySingleton@@0PAV1@A)
</pre>
Any idea?