The Command pattern explained

The Command pattern is exactly the pattern that solves our problem. The purpose of the Command pattern is to decouple the requester of an action from the object that performs the action. That is exactly the problem we have. Our requester is the button, and it needs to be decoupled from whatever specific function call will be made. The Command pattern takes our concept of a function pointer and wraps it into a class with a simple interface for performing the function call. However, this pattern allows us more flexibility. We will easily be able to encapsulate function pointers with multiple parameters, as well as with C++ object and member functions. Let's start off easy with just two simple functions that have the same parameter count and return type:

int Square(int x) 
{ 
  return x * x; 
} 

int Cube(int x) 
{ 
  return x*x*x; 
} 

The Command pattern encapsulates a request into an object, and it gives a common interface to perform that request. In our example...