Static array of method pointers

Question

I'm facing an error I dont understand.

I try to create and use a static array of method pointers. The declaration in my class looks like this:

static void (Client::*packetHandler[Op::handledOpcodeMax - Op::handledOpcodeMin + 1])(QByteArray &data);

Initialization takes place in my .cpp files is like that:

void (Client::*packetHandler[Op::handledOpcodeMax - Op::handledOpcodeMin + 1])(QByteArray &data);

Here comes the troubles, in one of my Client's class method I try to use this methods pointers' array. I tried several ways, for example :

(this->*packetHandler[_opcode])(data);

I said I didnt understand the problem, let me explain why. Running make on my code results in a proper compilation, tought, there is a problem when linking.

client.cpp:71: undefined reference to `Client::packetHandler'

This message is repeated 5 times.

Any help would be welcome. Thank you.

Answer 1

void (Client::*packetHandler[Op::handledOpcodeMax - Op::handledOpcodeMin + 1])(QByteArray &data); declares a global variable named packetHandler. You want to define your class variable, which needs an extra Client:: like so:

void (Client::*Client::packetHandler[Op::handledOpcodeMax - Op::handledOpcodeMin + 1])(QByteArray &data);

Answer 2

Client::*packetHandler is a member function pointer that points to a member function named Client::packetHandler. I'm not sure how to make a member function pointer that points to an arbitrary member function which is what you seem to want to do. I think George is right. You should consider using something like boost::function or std::tr1::function or write your own member function wrapper class.