grauzone Wrote:
> Simon TRENY wrote:
> > Hi there!
> >
> > I'm quite new at D and I'm still just playing with it, but there is a thing
> > that I find currently missing. Sometimes, I'd like to be able to return a
> > struct by reference and not by value. For example, in the following example:
> >
> > struct Position {
> > float x;
> > float y;
> > }
> >
> > class Object {
> > private Position m_position;
> >
> > public Position position() {
> > return m_position;
> > }
> > }
> >
> > I'd like to be able to write things like this: myObject.position.x = 43 to
> > actually change the position of the object. But right now, since "position"
> > is a struct, it is returned by value and not by reference, and then the
> > previous instruction won't change the position of the object, but it will
> > work on a copy of the position field.
> >
> >
> > Here is the solutions that I can see to this problem:
> >
> > - Returning a pointer to the position: "public Position *position() { ...
> > }", but I'd like to keep my code as free from pointers as possible.
> > - Make "Position" a class and not a struct. That could be a solution, but
> > then, when I'll do things like "Position pos = object.position; pos.x =
> > 43;", it will effectively change the position of the object, which I
> > wouldn't like with this syntax.
> >
> > Actually, I'd like to be able to do a thing like this:
> > public ref Position position() {
> > return m_position;
> > }
> > which would be the equivalent form to passing structs by reference in a
> > parameter.
> >
> > Is there a way to do this in D?
>
> Yes. Make the variable public.
>
> class Object {
> Position position;
> }
>
> This code is even simpler than your's above. Incredible, isn't it?
Ok, but then, what if I'd like to make the variable "read-only"? i.e.
preventing the user from writing things like this:
myObject.position = pos2;
>
> > Regards,
> > Simon
> >
