Thread: Inherited syntax

I have been studying the source code for FLTK and I've noticed syntax I've never come across before.

Code:

Fl_Button::Fl_Button(int X, int Y, int W, int H, const char *l)
: Fl_Widget(X,Y,W,H,l) {

Now in this instance Fl_Button inherits from Fl_Widget so am I correct to assume that :Fl_Widget(X,Y,W,H,l) is just setting the parameters in the Fl_Widget constructor using parameters passed into the Fl_Button constructor (as the Fl_Widget constructor is assumedly called as well) and then the Fl_Button constructor does whatever class specific constructor things..

Have I got the correct idea here?

Great, seemed logical enough. Thanks.

Note that you should be using that same syntax to initialize the member variables of the class as well. It is called the initializer list.