Many times called, once called back init function
If you have done any programming to build extensions or plugins in the form of a dll or shared object, then you probably know the purpose of this class or funcion structure, if not then keep reading.
Suppose that your code is sitting inside a dll that doesn&squo;t have a dll main or init function that you can force to be called, now suppose that you have some initialization routine that needs to be called once and only once but doesn&squo;t necessarily need a cleanup or shutdown function. One type of example might be RegisterClass although I believe that there is an UnregisterClass, and the other might be InitCommonControls; I don&squo;t believe there is an uninitcommoncontrols.
Defining a Function Pointer
