Request for a more powerful template specialization feature

[Jonathan M Davis via Digitalmars-d]

On Friday, July 14, 2017 4:45:10 PM MDT Andrei Alexandrescu via Digitalmars-
d wrote:
> On 07/14/2017 04:29 PM, Jonathan M Davis via Digitalmars-d wrote:
> > I'd guess that you'd use staticIndexOf an check for
> > -1 to implement it
>
> Given that constraints are user-facing, having a forwarding one-liner
> may be justifiable. -- Andrei

Possibly. It's hard to know sometimes when a one line wrapper is a big
enough boost to usability to standardize. I could see this being such a
case.

staticIndexOf is a bit unwieldy, and I've rarely used it, but when I have,
I think that I've always used it to check whether somehing is present rather
than getting an actual index.

Another tough example would be takeWhile/dropWhile. We already of until and
find, which do the same things respectively but with the opposite predicate
such that they're arguably too simple to be worth adding, but at the same
time, if you have to negate your predicates often enough, having takeWhile
and dropWhile would be a definite boon (also, for many folks, takeWhile and
dropWhile are obvious in a way that until or find might not be - especially
until). Timon was complaining bitterly the other day about the lack of
takeWhile:

https://issues.dlang.org/show_bug.cgi?id=4535

IIRC, I tried to add those several years ago, but you vetoed them on the
grounds that simply negating the predicate was trvial, which is certainly
true, albeit less user-friendly. I don't know what the correct answer is
though. Sometimes, it's clear that adding a one-liner is a pointless
wrapper, whereas in other cases, it seems like a definite usabiliy
improvement.

- Jonathan M Davis