Declaring a Static Member of a Function Pointer

[Brandon]

In a templated class I wrote, there is a public typedef for a function
pointer. The class has an instance of the function pointer as a
private member. That pointer is declared as static so I need to
declare an instance of the pointer. So, I tried using the keyword
typename to declare the static member. I don't get any syntax errors
but the pointer's name shows up in an "undefined symbol" error at
compile time. Have a look at this example code and tell me if you can
stop an error.


template <class T>
class XYZ
{
public:
// Function pointer type
typedef int(*funcPtr)(T ,T);
protected:
// Static function pointer
static funcPtr myCallback;
};

// XYZ's static function pointer declaration
typename XYZ<class T>::funcPtr XYZ<class T>::myCallback ;

[John Harrison]

Re: Declaring a Static Member of a Function Pointer

On 7 Aug 2004 19:44:15 -0700, Brandon <bcr07548@creig hton.edu> wrote:
[color=blue]
>
> template <class T>
> class XYZ
> {
> public:
> // Function pointer type
> typedef int(*funcPtr)(T ,T);
> protected:
> // Static function pointer
> static funcPtr myCallback;
> };
> // XYZ's static function pointer declaration
> typename XYZ<class T>::funcPtr XYZ<class T>::myCallback ;[/color]

You need to start any template declaration with the keyword template. I'd
try

template <class T>
typename XYZ<T>::funcPtr XYZ<T>::myCallb ack;

and make sure that goes in a header file.

john

[Arne Adams]

Re: Declaring a Static Member of a Function Pointer

bcr07548@creigh ton.edu (Brandon) wrote in message news:<24f6b708. 0408071844.75e6 c4ab@posting.go ogle.com>...[color=blue]
> compile time. Have a look at this example code and tell me if you can
> stop an error.
>
>
> template <class T>
> class XYZ
> {
> public:
> // Function pointer type
> typedef int(*funcPtr)(T ,T);
> protected:
> // Static function pointer
> static funcPtr myCallback;
> };
>
> // XYZ's static function pointer declaration
> typename XYZ<class T>::funcPtr XYZ<class T>::myCallback ;[/color]

try:

template<class T> typename XYZ<T>::funcPtr XYZ<T>::myCallb ack;

Arne