countUntil for SortedRange

[John Colvin via Digitalmars-d-learn]

On Tuesday, 11 August 2015 at 19:30:02 UTC, Laeeth Isharc wrote:
> Hi.
>
> Basic question: suppose I have a SortedRange and want to find 
> the index of the first entry of an array of structs matching a 
> needle struct.
>
> What's the best way to do that?  It's not clear that countUntil 
> treats a SortedRange specially.
>
> I could get the lowerBound and then length or walkLength (can't 
> remember which applies).
>
> But I figure there must be a better way.
>
> Thanks.
>
>
> Laeeth.

Yeah, I was wrong when I said it was treated specially. 
lowerBound followed by length should do it without any notable 
inefficiencies. I guess you could wrap it as `sortedCountUntil` 
for convenience if you like.