Properties: a.b.c = 3

[Zhenyu Zhou]

Chad J Wrote:
> Zhenyu Zhou wrote:
> > 
> > What about:
> > 
> > class Widget
> > {
> >  	Rectangle _rect;
> >  	immutable(Rectangle) rect() const { return _rect; }
> >  	Rectangle rect(Rectangle r) { return _rect = r; }
> > }
> 
> You'll fall into the trap unless you know about immutable.  Said another
> way: the default is unsafe.  Also this still isn't very useful, as it
> still requires the calling programmer to manually break apart the
> accesses and will not work for things like "array.length++;" which were
> errors already.
> 
> So even if newbies were omniscient and always made their getters
> immutable, all you'd have accomplished is turning a debugging session
> into an annoyance.  Noble, but all too bitter when a complete solution
> is within grasp.

Maybe this is what you want
ref rect() { return _rect; }

But I would still return const type because it's unsafe to change the rect without calling its setter

e.g.
Rectangle rect(Rectangle r) {
  _rect = r;
  redraw(); 
  return _rect; 
}

If you allow
widget.rect.w = 200;
widget.rect.h = 100;
you will have to write much more code to handle the painting correctly. 
and we don't want to call redraw twice here