如何初始化参数化模板 class 的 static 成员

Question

I don't think my question is a duplicate of this one .

what I try to do:

template<const char* szFunctionName>
class CReentranceLock
{
public:
    CReentranceLock(){}
    ~CReentranceLock(){}
    bool isLocked(){return s_bLock;}
    void setLocked(bool b)
    {
        const bool Result=(bool)InterlockedCompareExchange(
                    (unsigned long *)&s_bLock, b, !b);
    }

private:
    static bool s_bLock;
};

template<const char* szFunctionName>
bool CReentranceLock<const char*szFunctionName>::s_bLock=false; 
// error C2146: syntax error : missing ',' before identifier 'szFunctionName'

implying that all instances of CReentranceLock would have their own static, relying on the const char address of the function name passed as a parameter of the template.

and that could be used like this:

void CMyObject::InAnyFunction()
{
    const char* szFunctionName = __FUNCTION__; 
    CReentranceLock<szFunctionName> lock; // Edit: <- this doesn't work
    if(lock.isLocked()) return;
    lock.setLocked(true);
    /// business code
   lock.setLocked(false);
}

well that's only the theory... and unfortunately this doesn't compile under visual 2010, at the line where I try to initialize the statics.

error C2146: syntax error : missing ',' before identifier 'szFunctionName'

what am I doing or thinking wrong?

PS: and I am not dealing with the fact that reentrance is smelling like an awful design (in MFC), I know, I am lost in the middle of it;-)

Edit : though the answer below is good, and the definition compiles... my use in CMyObject::InAnyFunction() with a const char * as a template-parameter available at compile time seems to be wrong. :-(

Answer 1

bool CReentranceLock<const char*szFunctionName>::s_bLock=false; 

This should be:

bool CReentranceLock<szFunctionName>::s_bLock=false; 

Answer 2

Just change the line to

bool CReentranceLock<szFunctionName>::s_bLock=false;