On Tue, 14 Oct 2025 at 17:08, Yuao Ma <[email protected]> wrote:
>
> Hi Hewill and Jonathan,
>
> On Tue, Oct 14, 2025 at 11:39 PM Hewill Kang <[email protected]> wrote:
> >
> > 1. The prefix ranges:: in ranges::__detail::__is_integer_like can be
> > removed.
>
> It can't. views has its own __detail namespace.
>
> > 2. Parameters should not be passed by reference; otherwise, const int i =
> > 0; std::views::indices(i); will fail because const int& does not satisfy
> > __is_integer_like.
>
> Yes I figure that out with the new testcase. Done.
>
> > 3. operator() can be static.
>
> I think I'll stick to the style of the existing functions.
static operator() is a C++23 feature, so wasn't an option for the
original C++20 views.
I'm not sure it makes much difference on the ABI used for most of our
supported targets, and it should be optimized away anyway. In fact, we
could add [[__gnu__::__always_inline__]] to the operator() here, since
it's incredibly simple.
> The testcase got updated, testing against different type and size. But
> ranges::__detail::max_{size, diff}_type not working here:
Ah yes, that's a problem. If you create
views::indices(ranges::distance(views::iota(0ULL, 1ULL))) then you
need to create an iota_view of the difference type of iota(0ULL,
1ULL), but that can't be represented. You would need an integer-like
type wider than our widest integer-like type.
That might be a defect in the wording for views::indices, but that's
not your concern. There's no need to test it with that type then.
