On Tue, 14 Jul 2026 at 05:30, Patrick Palka <[email protected]> wrote:
>
> For segmented iterators, ranges::distance is equivalent to the sum of
> ranges::distance of each of its segments.
There's no [PATCH v2 2/2] that supersedes this, right?
OK for trunk if this is the right one.
>
> PR libstdc++/123211
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/ranges_base.h (__distance_fn::operator()): For
> the non-sized-sentinel overload,
> ---
> libstdc++-v3/include/bits/ranges_base.h | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/libstdc++-v3/include/bits/ranges_base.h
> b/libstdc++-v3/include/bits/ranges_base.h
> index ce1c40fc17f6..7f169feaa6b1 100644
> --- a/libstdc++-v3/include/bits/ranges_base.h
> +++ b/libstdc++-v3/include/bits/ranges_base.h
> @@ -994,6 +994,16 @@ namespace ranges
> constexpr iter_difference_t<_It>
> operator()[[nodiscard]](_It __first, _Sent __last) const
> {
> + if constexpr (__segmented_iterator<_It> && same_as<_It, _Sent>)
> + {
> + iter_difference_t<_It> __n = 0;
> + std::__for_each_segment(__first, __last, [this, &__n](auto
> __first, auto __last) {
> + __n += iter_difference_t<_It>(this->operator()(__first,
> __last));
> + return __last;
> + });
> + return __n;
> + }
> +
> iter_difference_t<_It> __n = 0;
> while (__first != __last)
> {
> --
> 2.55.0.141.g55526a1826
>
