Reverse range adapter

[David Blaikie]

I'm OK calling it 'reverse' as you have (since it has just the one argument
it shouldn't be ambiguous with the iterator versions)

* These functions shouldn't be 'static'
* Could you try using non-member begin/end in the second version - that
should allow it to work with arrays. Give it a go/add a test?
* Maybe test the case where a container has rbegin/rend and begin/end to
ensure we still favor the rbegin/rend (and that it's not ambiguous?) -
presumably they're more efficient, if they're provided?

& the reason you don't need explicit SFINAE is because you put the
interesting expressions in the return type - so they're part of the SFINAE
condition already, conveniently.

I think Saleem (cc'd) had an existing implementation of something like this
that he might be willing to provide some insight from?

On Tue, Jul 28, 2015 at 9:43 AM, Pete Cooper <peter_cooper at apple.com> wrote:

> Hi David
>
> Please find attached a patch for a reverse range adapter.  Its based on
> feedback you gave in
> http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150720/289410.html
> .
>
> There are 2 versions.  The first uses rbegin()/rend(), the second
> constructs std::reverse_iterators around begin()/end().
>
> I was surprised to find I didn’t need enable_if or any other such tricks.
>
> I’ve updated a single use of the pattern ‘for auto x :
> make_range(rbegin(), rend())’ to the new reverse method.
>
> I was considering reverse_range instead as a name to avoid confusion with
> std::reverse.  I’d prefer to not do make_reverse_range just to save on
> characters.
>
> Feedback welcome.
>
> Cheers,
> Pete
>
>
>
>
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