On Tue, 15 Jun 2021 at 22:33, Jonathan Wakely wrote:
>
> On Tue, 15 Jun 2021 at 21:32, Tim Song wrote:
> >
> > CPOs are specified as actual semiregular function objects that can be
> > copied and constructed freely, so it seems a bit hostile to make them
> > final/non-addressable? (It's debatable whether the type of a CPO is a
> > type "specified in the C++ standard library" for which [derivation]/4
> > would apply.)
>
> I noticed that libstdc++ was failing some libc++ tests, but that was
> only for ranges::advance etc and not the CPOs. I guess I got a bit
> carried away, and it shouldn't apply to the CPOs, only the
> [range.iter.ops] "function templates" (which are not really function
> templates).

This reverts the changes to the [range.access] CPOs, and improves some
tests slightly.

Tested powerpc64le-linux. Pushed to trunk.