Expected compile-time constant expression

Does anyone know why the following works:

Code:

class Test
{
public:
	void Set(int) {}
	int Get() {}

	Test(): m_Test(this) {};
	Stuff::CUtilityMember<int, Test, int, &Test::Get, &Test::Set> m_Test;
};

But not the following:

Code:

class Test
{
public:
	void Set(int) {}
	int Get() {}

	Test(): m_Test(this) {};
	Stuff::CUtilityMember<int, Test, int, NULL, NULL> m_Test;
};

?

CUtilityMember looks like:

Code:

#define Template	template \
					< \
						typename Type, typename Class, typename ReturnType, \
						/*typename*/ /*ParamPolicy<ReturnType>::Type*/int (Class::* GetFunction)(), \
						void (Class::* SetFunction)(/*typename ParamPolicy<Type>::Type*/int NewData) \
					>

Error 3 error C2975: 'GetFunction' : invalid template argument for 'Stuff::CUtilityMember', expected compile-time constant expression g:\w00t\visual studio 2008\projects\stuff\utilitymember.h 65
Error 4 error C2975: 'SetFunction' : invalid template argument for 'Stuff::CUtilityMember', expected compile-time constant expression g:\w00t\visual studio 2008\projects\stuff\utilitymember.h 65

I've a feeling it's with 'int NewData'... try replacing that with a compile-time constant expression, like 42, for example and see if that compiles. Just guessing. I can't replicate the error with what you've provided here.

Oh! I didn't even SEE that error parameter name there. I just moved those from the class, so of course I made a mistake. Meh.
But it still doesn't solve the problem by removing it.
I can attach the source for anyone to try to compile and see if they can figure out why it's not accepting 0 as a compile-time expression.

I'm not sure why, but if I put the body of the constructor within the class definition it compiles...

Code:

	class CUtilityMember
	{
	private:
		Type Data;
		//typedef const ReturnType& (Class::*GetFncPointer)();
		//typedef void (Class::*SetFncPointer)(const Type& NewData);
		//GetFncPointer m_pGet;
		//SetFncPointer m_pSet;
		Class* m_pClass;
	
	public:
    CUtilityMember(Class* pClass) //, GetFncPointer pGet = NULL, SetFncPointer pSet = NULL);
    : m_pClass(pClass){  }

		CUtilityMember(typename ParamPolicy<ReturnType>::Type NewData, Class* pClass); //, GetFncPointer pGet = NULL, SetFncPointer pSet = NULL);
		CUtilityMember& operator = (typename ParamPolicy<ReturnType>::Type NewData);
		operator Type () const;
	};

.

Edit: Also doing this works too:

Code:

#define TemplateArgs\
						typename Type, typename Class, typename ReturnType, \
						/*typename*/ /*ParamPolicy<ReturnType>::Type*/int (Class::* GetFunction)(), \
						void (Class::* SetFunction)(/*typename ParamPolicy<Type>::Type*/int) 
#define Template	template<TemplateArgs> 

// ...

	Template CUtilityMember<TemplateArgs>:://...
	Template CUtilityMember<TemplateArgs>:://...

etc

Weird. You're right that it works if the constructor is placed in the class body...