Apple

On Aug 27, 2007, at 2:29 PM, Brant Sears wrote:

Hi. I have a question about static members of a templated class. I am getting an undefined symbols error from the linker.
My templated class:

template <class T> class RefCountPtr
{
public:
RefCountPtr(T *ptr) : p(ptr) {
QMutexLocker lckr(&cmLock);
++countMap[p];
}
~RefCountPtr() {
QMutexLocker lckr(&cmLock);
--countMap[p];
if (countMap[p] == 0) {
delete p;
}
}

T* operator->() {
return p;
}

bool isNull() {
return (NULL==p);
}

private:
T * p;
static QMutex cmLock;
static map<T *, int> countMap;
};

Then in another header, I have this:
typedef RefCountPtr<Credentials> CredentialsPtr

Then in a .cpp file, I have the following:
template <> QMutex RefCountPtr<Credentials>::cmLock;
template <> map<Credentials*, int> RefCountPtr<Credentials>::countMap;

I am seeing the following linker error:

/usr/bin/ld: Undefined symbols:
RefCountPtr<Credentials>::cmLock
RefCountPtr<Credentials>::countMap

I thought I was defining the static members. Any idea why I'm seeing this and what I can do to fix it?

TIA

Brant Sears