This page is a snapshot from the LWG issues list, see the Library Active Issues List for more information and the meaning of C++23 status.
chunk_view::outer-iterator::value_type::size
should return unsigned typeSection: 26.7.29.4 [range.chunk.outer.value] Status: C++23 Submitter: Hewill Kang Opened: 2022-06-01 Last modified: 2023-11-22
Priority: Not Prioritized
View all other issues in [range.chunk.outer.value].
View all issues with C++23 status.
Discussion:
Currently, the size
function of chunk_view::outer-iterator::value_type
returns
the result of ranges::min
, since the operands are of type range_difference_t<V>
,
this will return a signed type, which is inconsistent with the return type of size
of the
forward
-version of chunk_view::iterator::value_type
(26.7.29.7 [range.chunk.fwd.iter]),
which always returns an unsigned type.
I think it's more reasonable to return an unsigned type, since this is intentional behavior and
doesn't fall back to using the default view_interface::size
.
And if LWG 3646(i) is eventually adopted, there's no reason why it shouldn't be made
unsigned.
[2022-06-21; Reflector poll]
Set status to Tentatively Ready after five votes in favour during reflector poll.
[2022-07-15; LWG telecon: move to Ready]
[2022-07-25 Approved at July 2022 virtual plenary. Status changed: Ready → WP.]
Proposed resolution:
This wording is relative to N4910.
Modify 26.7.29.4 [range.chunk.outer.value] as indicated:
constexpr auto size() const requires sized_sentinel_for<sentinel_t<V>, iterator_t<V>>;-4- Effects: Equivalent to:
return to-unsigned-like(ranges::min(parent_->remainder_, ranges::end(parent_->base_) - *parent_->current_));