Multiple Alias This

[Andrei Alexandrescu]

dsimcha wrote:
> Is the limitation that one may only have one alias this per class/struct a
> temporary limitation that will be removed once higher-priority stuff is
> finished and some ambiguities are resolved, or are things likely to stay this
> way?  On the one hand, allowing multiple alias this would cause ambiguities
> similar to multiple inheritance.  On the other hand, only being able to define
> one implicit cast per class/struct is pretty limiting and allowing only one
> alias this seems like a huge cop-out.

Yah, it's a temporary limitation. However, removing it is nontrivial. D 
tries to avoid first-fit rules and best-fit is difficult.

Note that if you have control over the types you can implement a sort of 
a first-fit by distributing the "alias this" declaration to each type. 
(This is very clumsy.)

Andrei