Property discussion wrap-up

[Jonathan M Davis]

On Friday, February 01, 2013 16:03:41 TommiT wrote:
> On Friday, 1 February 2013 at 14:49:48 UTC, TommiT wrote:
> > As far as I know, the obove kind of thing isn't possible with
> > the current state of affairs; with @property attribute, you
> > cannot provide the extra level of encapsulation that checks
> > that the sum of 'speed' and 'sneak' isn't above 5.
> 
> ...and if the specification is changed so that:
> 
> struct S
> {
>      T _prop;
> 
>      @property T prop() const
>      {
>          return _prop;
>      }
> 
>      @property void prop(T t)
>      {
>          assert(t <= 5);
>          _prop = t;
>      }
> }
> ...
> S s;
> s.prop += 3;
> 
> ...gets lowered to s.prop = (s.prop + 3); Then that sucks because
> now T is forced to provide the binary + operator.

And why is that a problem? If you expect s.pop += 3 to work, how could you not 
expect + to work on the type of prop? You're generally doing something wrong 
if your type defines += and not + anyway, so I really don't see the problem 
here.

- Jonathan M Davis