Suggestion: Operator `in` for slices

[Era Scarecrow]

On Tuesday, 4 January 2022 at 18:23:33 UTC, Nick Treleaven wrote:
> It would make sense to implement `in` for SortedRange, but 
> there is no use case for returning a pointer. You already have 
> the value on the left hand side, the only reason for a pointer 
> would be to mutate the element in the range.

  Sorry, i was somehow thinking there was a key/value pair in this 
and not just a normal sorted block.

  But yes there may still be use cases. Consider i do opCmp on a 
struct, and it only does comparisons on say a name portion (*Or 
UPC or some other immutable property ID*), but no other part of 
the stored data. The name/ID would be how it's sorted; But any 
attached data which is non-sorted would be inaccessible 
otherwise. This could be phone number, address, grades, just 
about anything (*and those items could be changed without 
changing the sorting order*)

  Though you can probably do 2 steps it seems like a bit of extra 
pointless work to me. Or maybe AA's are a better choice in that 
case. I'm not sure.