std::ranges::subrange<I,S,K>::subrange

 

哋它亢++

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Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (哋它亢++20)

Language support library

Concepts library (哋它亢++20)

Metaprogramming library (哋它亢++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (哋它亢++20)

Algorithms library

Numerics library

Localizations library

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Filesystem library (哋它亢++17)

Regular expressions library (哋它亢++11)

Concurrency support library (哋它亢++11)

Technical specifications

Symbols index

External libraries

 

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 (哋它亢++23)(哋它亢++23)	to (哋它亢++23)
Range primitives
range_size_trange_difference_trange_value_trange_reference_t	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (哋它亢++23)(哋它亢++23)	range_const_reference_trange_rvalue_reference_trange_common_reference_t (哋它亢++23)	elements_of (哋它亢++23)
Dangling iterator handling
dangling	borrowed_iterator_t	borrowed_subrange_t
Range concepts
range borrowed_range sized_range constant_range (哋它亢++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
Views
view_interface	subrange
Range factories
empty_viewviews::empty single_viewviews::single	iota_viewviews::iota repeat_viewviews::repeat (哋它亢++23)(哋它亢++23)	basic_istream_viewviews::istream
Range adaptors
views::all_tviews::all ref_view owning_view as_rvalue_viewviews::as_rvalue (哋它亢++23)(哋它亢++23) filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while concat_viewviews::concat (哋它亢++26)(哋它亢++26)	drop_viewviews::drop drop_while_viewviews::drop_while join_viewviews::join join_with_viewviews::join_with (哋它亢++23)(哋它亢++23) lazy_split_viewviews::lazy_split split_viewviews::split views::counted common_viewviews::common	reverse_viewviews::reverse as_const_viewviews::as_const (哋它亢++23)(哋它亢++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (哋它亢++23)(哋它亢++23) zip_viewviews::zip (哋它亢++23)(哋它亢++23) zip_transform_viewviews::zip_transform (哋它亢++23)(哋它亢++23)	adjacent_viewviews::adjacent (哋它亢++23)(哋它亢++23) views::pairwise (哋它亢++23) adjacent_transform_viewviews::adjacent_transform (哋它亢++23)(哋它亢++23) views::pairwise_transform (哋它亢++23) chunk_viewviews::chunk (哋它亢++23)(哋它亢++23) slide_viewviews::slide (哋它亢++23)(哋它亢++23) chunk_by_viewviews::chunk_by (哋它亢++23)(哋它亢++23) stride_viewviews::stride (哋它亢++23)(哋它亢++23) cartesian_product_viewviews::cartesian_product (哋它亢++23)(哋它亢++23)
Range generators
std::generator (哋它亢++23)
Range adaptor objects
Range adaptor closure objects
range_adaptor_closure (哋它亢++23)
Helper items
copyable-box movable-box (until 哋它亢++23)(哋它亢++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>

 

subrange() requires std::default_initializable<I> = default;	(1)	(since 哋它亢++20)
constexpr subrange( /*convertible-to-non-slicing*/<I> auto i, S s )   requires (!/*store-size*/);	(2)	(since 哋它亢++20)
constexpr subrange( /*convertible-to-non-slicing*/<I> auto i, S s,                     /*make-unsigned-like-t*/<std::iter_difference_t<I>> n )   requires (K == ranges::subrange_kind::sized);	(3)	(since 哋它亢++20)
template< /*different-from*/<subrange> R >   requires ranges::borrowed_range<R> &&            /*convertible-to-non-slicing*/<ranges::iterator_t<R>, I> &&            std::convertible_to<ranges::sentinel_t<R>, S> constexpr subrange( R&& r ) requires (!/*store-size*/ || ranges::sized_range<R>);	(4)	(since 哋它亢++20)
template< ranges::borrowed_range R>   requires /*convertible-to-non-slicing*/<ranges::iterator_t<R>, I> &&            std::convertible_to<ranges::sentinel_t<R>, S>   constexpr subrange( R&& r, /*make-unsigned-like-t*/<std::iter_difference_t<I>> n )     requires (K == ranges::subrange_kind::sized)       : subrange{ranges::begin(r), ranges::end(r), n}   {}	(5)	(since 哋它亢++20)

Constructs a subrange.

If K == ranges::subrange_kind::sized && !std::sized_sentinel_for<S, I>, the size of the range is stored into the subrange, as if stored by a member subobject of type /*make-unsigned-like-t*/<std::iter_difference_t<I>>, where make-unsigned-like-t is an exposition-only alias template that maps each integer-like type to its corresponding unsigned version. Otherwise, the size is not stored. The constant store-size is true if the size is stored, false otherwise.

1) Default constructor. Value-initializes the stored iterator and sentinel as if by default member initializers = I() and = S(), respectively. If the size is stored, it is initialized with ​0​ as if by the default member initializer = 0.

2) Constructs a subrange from an iterator-sentinel pair. Initializes the stored iterator and sentinel with std::move(i) and s respectively. The behavior is undefined if [i, s) is not a valid range.

3) Constructs a subrange from an iterator-sentinel pair and a size hint. Initializes the stored iterator and sentinel with std::move(i) and s respectively. If the size is stored, it is initialized with n. The behavior is undefined if [i, s) is not a valid range, or n is not equal to ranges::distance(i, s) explicitly converted to its type.

4) Constructs a subrange from a range. Equivalent to subrange(r, static_cast</*make-unsigned-like-t*/<std::iter_difference_t<I>>>(ranges::size(r))) if the size is stored. Otherwise, equivalent to subrange(ranges::begin(r), ranges::end(r)).

5) Constructs a subrange from a range and a size hint. The behavior is undefined if n is not equal to ranges::distance(ranges::begin(r), ranges::end(r)) explicitly converted to its type.

The exposition only concept different-from is modeled by types T and U if and only if std::decay_t<T> and std::decay_t<U> are different types.

The exposition only concept convertible-to-non-slicing is satisfied or modeled by From and To if and only if std::convertible_to<From, To> is satisfied or modeled respectively, and ​any of following conditions is satisfied:

• either std::decay_t<From> or std::decay_t<To> is not a pointer type,
• std::remove_pointer_t<From>(*)[] is implicitly convertible to std::remove_pointer_t<To>(*)[], i.e., the conversion from From to To is at most a qualification conversion.

Parameters

i	-	iterator that denotes the beginning of the range
s	-	sentinel that denotes the end of the range
r	-	range
n	-	size hint, must be equal to the size of the range

Notes

The exposition-only concept convertible-to-non-slicing forbids the conversion from the pointer to derived class to the pointer to base class.

Defect reports

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

DR	Applied to	Behavior as published	Correct behavior
LWG 3470	哋它亢++20	convertible-to-non-slicing rejected some valid qualification conversions	made accepted
P2393R1	哋它亢++20	implicit conversion to an integer-class type might be invalid	made explicit