Just where has this language gone wrong?

[monarch_dodra]

On Sunday, 22 July 2012 at 21:10:08 UTC, Andrei Alexandrescu 
wrote:
> On 7/22/12 12:32 PM, David Nadlinger wrote:
>> On Sunday, 22 July 2012 at 03:06:28 UTC, Jens Mueller wrote:
>>> Where is argmin defined? I couldn't find it.
>>
>> On the slide before that… ;)
>
> I think argmin is intuitive, popular, and useful enough to 
> warrant a presence in std.algorithm. Would anyone want to do 
> the honors?
>
>
> Thanks,
>
> Andrei

Are you asking for the _actual_ argmin as defined in the paper?

Because I think it would be much better if we provided an 
overload for the existing minPos/minRange to accept a unary pred:

----
Range minPos(alias pred, Range)(Range range)
   if (is(typeof(unaryFun!pred(range.front))))
{
   ...
}
----
Tuple!(ElementType!(Range), size_t)
minCount(alias pred, Range)(Range range)
   if (is(typeof(unaryFun!pred(range.front))))
{
   ...
}
----

Where pred if the unary weight function. This code would then 
work as such:

----
auto m = s.minPos!((x) => x.length).front;
----
auto m = s.minCount!((x) => x.length)[1];
----

Both versions require an extra .front/[1], but that's because 
that's just how the algorithms work.

I actually _just_ rewrote these two methods (they are in my pull 
requests). I'm on it if you you like the idea of being able to 
call these functions with a unary predicated (I do): It sure 
beats writing "(a, b) => pred(a) < pred(b)" when you could just 
write "a => pred(a)"