deduction guides for std::ranges::subrange

 

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Ranges library

Range access begin cbegin   end cend rbegin crbegin   rend crend size ssize   data cdata empty

Range conversions std::from_range_t std::from_range (C++23)(C++23)     to (C++23)

Dangling iterator handling dangling borrowed_iterator_t borrowed_subrange_t

Range primitives
range_size_trange_difference_trange_value_t elements_of (C++23)	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_reference_trange_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)

Range concepts
range borrowed_range    sized_range	common_range view viewable_range	input_range output_range forward_range	bidirectional_range    random_access_range contiguous_range	constant_range (C++23)

Views
view_interface	subrange

Range factories
empty_viewviews::empty	single_viewviews::single	basic_istream_viewviews::istream	iota_viewviews::iota	repeat_viewviews::repeat (C++23)(C++23)

Range adaptors
views::all_tviews::all ref_view owning_view as_rvalue_viewviews::as_rvalue (C++23)(C++23)   filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while concat_viewviews::concat (C++26)(C++26)	drop_viewviews::drop drop_while_viewviews::drop_while join_viewviews::join join_with_viewviews::join_with (C++23)(C++23)   lazy_split_viewviews::lazy_split split_viewviews::split views::counted common_viewviews::common	reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)

Range generators std::generator (C++23)

Range adaptor closure objects range_adaptor_closure (C++23)

Range adaptor objects

Helper items
copyable-box movable-box (until C++23)  (C++23)	simple-view non-propagating-cache

 

std::ranges::subrange

Member functions

subrange::subrange

subrange::operator PairLike

Observers

subrange::begin

subrange::end

subrange::empty

subrange::size

Iterator operations

subrange::advance

subrange::next

subrange::prev

Deduction guides

Non-member functions

get(std::ranges::subrange)

Helper types

subrange_kind

tuple_size<std::ranges::subrange>

tuple_element<std::ranges::subrange>

 

Defined in header <ranges>
template< std::input_or_output_iterator I, std::sentinel_for<I> S > subrange(I, S) -> subrange<I, S>;	(1)	(since C++20)
template< std::input_or_output_iterator I, std::sentinel_for<I> S > subrange(I, S, /*make-unsigned-like-t*/<std::iter_difference_t<I>>) ->     subrange<I, S, ranges::subrange_kind::sized>;	(2)	(since C++20)
template< ranges::borrowed_range<R> > subrange(R&&) ->     subrange<ranges::iterator_t<R>, ranges::sentinel_t<R>,              (ranges::sized_range<R> ||               std::sized_sentinel_for<ranges::sentinel_t<R>,               ranges::iterator_t<R>>) ?              ranges::subrange_kind::sized : ranges::subrange_kind::unsized>;	(3)	(since C++20)
template< ranges::borrowed_range<R> > subrange(R&&, /*make-unsigned-like-t*/<ranges::range_difference_t<R>>) ->     subrange<ranges::iterator_t<R>, ranges::sentinel_t<R>,              ranges::subrange_kind::sized>;	(4)	(since C++20)

These deduction guides are provided for std::ranges::subrange.

1) Deduces the template arguments from the type of iterator and sentinel. The subrange is sized if std::sized_sentinel_for<S, I> is satisfied, as determined by the default template argument.

2) Deduces the template arguments from the type of iterator and sentinel, while the size of range is specified. The subrange is always sized.

3) Deduces the template arguments from the type of range. The subrange is sized if the size can be obtained from the range or its iterator and sentinel.

4) Deduces the template arguments from the type of range, while the size of range is specified. The subrange is always sized.

For the definition of /* make-unsigned-like-t */, see make-unsigned-like-t .

Notes

While constructing the subrange object,

• for (1,2), the behavior is undefined if the iterator-sentinel pair does not denote a valid range,
• for (2,4), the behavior is undefined if the given size is not equal to the size of the range.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 3404	C++20	meaningless deduction guides from pair-like types were provided	removed