[AGENT++] C++ function within snmp++ callback

[Marek Malowidzki]

> Of course, one modern way would be to pass a pointer to a SnmpCallback
> object. Until now, nobody asked for such a change.
>
> class SnmpCallback
> {
>  public:
>  virtual void callback(int reason, Snmp *snmp, Pdu &pdu,
>                        SnmpTarget &target, void *cd) = 0;
> };
>

There is no need for any change, just add to this class a static member 
function that does the work described in earlier posts (that is, cast the 
"state" object to an SnmpCallback pointer and call its callback() function), 
which would be perfectly ok to be passed as the current callback function.

Also, there should probably be a bit more C++ stuff, e.g., a virtual 
destructor (with an implementation provided anyway!) and some overridden 
operators but I do not remeber all the details now (anyone interested should 
consult a good book on C++).

Marek