Operator overhaul

[Andrei Alexandrescu]

bearophile wrote:
> Andrei Alexandrescu:
>> There would be composition (of the kind usually addressed through 
>> expression templates), but we don't have a good solution to that
>> yet.
> 
> You really want to make D an awesome language :-)
> 
> I though that in D the expression templates stuff was left to be done
> by the AST macros, but if they don't come until D3, then a more
> specialized functionality may be used in the meantime... (if
> necessary even to be later removed in D3).

I agree. Anyhow, the floor is open for suggestions on how to overhaul 
the entire operator business. I'll tell you what is, to me, clearly dead 
wrong: whenever one implements any class that wants to overload a bunch 
of operators (number-like classes etc.) inevitably it boils down to 
repetitive code like this:

struct Whatever
{
     Whatever opAdd(Whatever rhs) { return member + rhs.member; }
     Whatever opSubtract(Whatever rhs) { return member - rhs.member; }
     ...
}

and lines and lines of brain damaged repetition, repetition, repetition. 
If we add opWhateverAssign that will get even worse. The challenge is, 
then, to define a way to overload operators that makes the classic 
applications of the feature short and sweet.


Andrei