mismatch and return value

[ketmar via Digitalmars-d-learn]

On Wednesday, 13 July 2016 at 09:59:30 UTC, celavek wrote:
> That goes into an infinite loop.

sure. let's read the docs: "Returns a tuple with the reduced 
ranges that start with the two mismatched values." so, if it will 
find mismatch, it will loop forever then, as you forgot to pop 
one of the values, making `mismatch` to infinitely return with 
the same ranges.

> What does mismatch return when it cannot
> actually find a mismatch?

let's read the doc again: "Returns a tuple with the reduced 
ranges that start with the two mismatched values." simple logic 
allows us to guess that it should return tuple with two empty 
ranges. and it really does.

> Is the return value immutable?

as with most other std.algo functions, the returned range has 
same properties as source range.