Proposal: Replace __traits and is(typeof(XXX)) with a 'magic namespace'.

[Andrei Alexandrescu]

Don wrote:
> [I'm moving this from deep inside a TDPL thread, since I think it's 
> important]
> 
> is(typeof(XXX)) is infamously ugly and unintuitive
> __traits(compiles, XXX) is more comprehensible, but just as ugly.
> 
> They are giving metaprogramming in D a bad name. I think we need to get 
> rid of both of them.
> 
> A very easy way of doing this is to replace them with a 'magic 
> namespace' -- so that they _look_ as though they're functions in a 
> normal module.
> Names which have been suggested include 'meta', 'traits', 'scope', 
> 'compiler'. Personally I think 'meta' is the nicest (and I suggested two 
> of the others <g>).

Another keyword, sigh...

And I'll be darned if "static" isn't the perfect fit :o).

> This would give us:
> 
> meta.compiles(XXX)
> meta.isArithmetic; // note, property syntax OK if no arguments
> meta.isArithmetic(int*);

isArithmetic is library-implementable. How would the library inject 
stuff in the meta namespace? Also my alarm goes off when seeing 
meta.isArithmetic(int*) instead of meta.isArithmetic!(int*), which is 
what the unwashed masses would have to do if they wanted to implement a 
similar facility. With time I've acquired a dim view of certain stuff in 
the language benefiting of untouchable advantages.


Andrei