Problem with template classes

[fisher55]

I have this classes:

class FunctMenuScreen
{
public:
	virtual ~FunctMenuScreen() = 0;
	virtual void operator()() = 0;
};


template<class FunctObj>
class FunctMenu : public FunctMenuScreen
{
typedef void (FunctObj::*FunctMenuAction)();

private:
	FunctObj* object;
	FunctMenuAction action;

public:
	FunctMenu(FunctObj*, FunctMenuAction);
	~FunctMenu() {};
	void operator()();
};

and in class MainMenu in some function I have this:

FunctMenu<MainMenu>* test = new FunctMenu<MainMenu>(this, &MainMenu::exit);

and linker show this error:

undefined reference to `FunctMenu<MainMenu>::FunctMenu(MainMenu*, void (MainMenu::*)())'

I compile it by GCC C++ Compiler on Linux.
What have I wrong? Please help, thank you

[Bazzy]

With templates you must keep the function definitions visible everywhere they are used, so you should keep them on the header

[fisher55]

That isn't the problem. Of course I have classes FunctMenuScreen and FunctMenu at one header file, their functions definitions in source file. And the same with class MainMenu.

[Galik]

The function definitions of a template class need to be in the header, not the source file.

[fisher55]

Thank you. How could I possible forget that!!! Thank you very much.