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lazy_split_view
needs to check the simpleness of Pattern
Section: 26.7.16.2 [range.lazy.split.view] Status: C++23 Submitter: Tim Song Opened: 2021-09-15 Last modified: 2023-11-22
Priority: Not Prioritized
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Discussion:
For forward ranges, the non-const
versions of lazy_split_view::begin()
and lazy_split_view::end()
returns an outer-iterator<simple-view<V>>
,
promoting to const
if V
models simple-view
. However, this failed to
take Pattern
into account, even though that will also be accessed as const
if
const
-promotion takes place. There is no requirement that const Pattern
is a range,
however.
[2021-09-24; Reflector poll]
Set status to Tentatively Ready after six votes in favour during reflector poll.
[2021-10-14 Approved at October 2021 virtual plenary. Status changed: Voting → WP.]
Proposed resolution:
This wording is relative to N4892.
Modify 26.7.16.2 [range.lazy.split.view], class template lazy_split_view
synopsis, as indicated:
namespace std::ranges { […] template<input_range V, forward_range Pattern> requires view<V> && view<Pattern> && indirectly_comparable<iterator_t<V>, iterator_t<Pattern>, ranges::equal_to> && (forward_range<V> || tiny-range<Pattern>) class lazy_split_view : public view_interface<lazy_split_view<V, Pattern>> { private: […] public: […] constexpr auto begin() { if constexpr (forward_range<V>) return outer-iterator<simple-view<V> && simple-view<Pattern>>{*this, ranges::begin(base_)}; else { current_ = ranges::begin(base_); return outer-iterator<false>{*this}; } } […] constexpr auto end() requires forward_range<V> && common_range<V> { return outer-iterator<simple-view<V> && simple-view<Pattern>>{*this, ranges::end(base_)}; } […] }; […] }