Proposal for SentinelInputRange

[Peter Alexander]

On Thursday, 28 February 2013 at 10:57:29 UTC, Walter Bright 
wrote:
>> My worry here is that we are setting a precedent for adding 
>> new range concepts.
>> If the only justification needed is that is saves a single 
>> operation in some
>> niche area of computing then we are opening the door to a LOT 
>> of different range
>> concepts.
>
> There are many cases where speed is a very big deal.

Yes, are we going to add new range categories every time there's 
a performance benefit to doing so?

has16ByteAlignedElements
hasUniqueElements
hasContiguousMemory
isMonotonic
isUnimodal
...
?