Delegates
---------------
- a type that enables the storage of references to functions.


Declaration
----------------
- like functions, but without a body, using the 'delegate' keyword.

    i.e. public delegate double processDelegate( double a, double b );


- it specifies a function signature consisting of a return type & parameter list.


Usage
---------------
- after the delegation definition, it can be used as a type to declare a variable.

    i.e. processDelegate process;


- the delegate variable can then be a reference to any function that has the same signature, ( ie return type & parameters ).

    i.e.
        static double Multiply( double p1, double p2 )
        {
            ...
        }

        static double Divide( double p1, double p2 )
        {
            ...
        }

        process = new processDelegate( Multiply );
         // process = new processDelegate( Divide ); <-- alternative

- once this is completed, the assigned function can be called using the delegate variable.

    i.e. process( p1, p2 );


PLEASE NOTE
---------------
- different from polymorphism, since only concerened with methods in base & child with same name.
- whereas delegates are to do with any method as long as they have the same signature !!
- the real purpose of delegates is to do with events/event handling.