Properties don't behave like variables?

[Jonathan M Davis]

On Monday, May 07, 2012 23:14:36 Jacob Carlborg wrote:
> On 2012-05-07 22:16, Michael wrote:
> > import std.stdio;
> > 
> > int pro = 1;
> > 
> > @property ref auto prop()
> > {
> > 
> >        return pro;
> > 
> > }
> > 
> > @property void prop(int value)
> > {
> > 
> >        pro = value;
> > 
> > }
> > 
> > void main()
> > {
> > 
> >        writeln(prop |= 2);
> > 
> > }
> 
> You're bypassing the getter.

You mean the setter?

Having a getter property function return by ref does allow you to use a 
property exactly as you would a variable, because you're operating on the ref 
that's returned. It also makes the property function nigh-on-useless, because 
then you're operating on its associated variable outside of the property 
function, making it so that you can no longer control access to it. You pretty 
much might as well make it a public variable at that point. Not to mention, 
even if returning by ref didn't have that problem, it would only work in cases 
where the property function was associated with an actual variable (since you 
have to return a ref to _something_), so it would still be impossible to 
emulate a variable with property functions which calculate the value from 
other variables or which grab the value from somewhere else (e.g. a database).

- Jonathan M Davis