std::ranges::crend

 

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Ranges library

Range access begin cbegin   end cend rbegin crbegin   rend crend size ssize   data cdata reserve_hint (C++26)   empty

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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)

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range borrowed_range    common_range	sized_range viewable_range    view	input_range output_range forward_range	bidirectional_range    random_access_range contiguous_range	approximately_sized_range (C++26) constant_range (C++23)

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

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views::all_tviews::all as_rvalue_viewviews::as_rvalue (C++23)(C++23)   filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while common_viewviews::common views::counted to_input_viewviews::to_input (C++26)(C++26)	ref_view drop_viewviews::drop drop_while_viewviews::drop_while lazy_split_viewviews::lazy_split split_viewviews::split join_viewviews::join join_with_viewviews::join_with (C++23)(C++23)   concat_viewviews::concat (C++26)(C++26) cache_latest_viewviews::cache_latest (C++26)(C++26)	owning_view 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

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

 

Defined in header <ranges>
Defined in header <iterator>
inlinenamespace/* unspecified */{     inlineconstexpr/* unspecified */ crend =/* unspecified */; }		(since C++20) (customization point object)
Call signature
template<class T >     requires /* see below */ constexpr/* see below */auto crend( T&& t );		(since C++20)

Returns a sentinel for the constant iterator(since C++23) indicating the end of a const-qualified(until C++23) range that is treated as a reversed sequence.

Let CT be conststd::remove_reference_t<T>& if the argument is an lvalue (i.e. T is an lvalue reference type), const T otherwise. A call to ranges::crend is expression-equivalent to ranges::rend(static_cast<CT&&>(t)).

(until C++23)

If the argument is an lvalue or ranges::enable_borrowed_range<std::remove_cv_t<T>> is true, then a call to ranges::crend is expression-equivalent to: std::const_sentinel<decltype(U)>(U) for some expression U equivalent to ranges::rend(possibly-const-range(t)). In all other cases, a call to ranges::crend is ill-formed, which can result in substitution failure when the call appears in the immediate context of a template instantiation.

(since C++23)

If ranges::crend(e) is valid for an expression e, where decltype((e)) is T, then CT models std::ranges::range, and(until C++23)std::sentinel_for<S, I> is true in all cases, where S is decltype(ranges::crend(e)), and I is decltype(ranges::crbegin(e)). Additionally, S models constant-iterator if it models input_iterator.(since C++23)

Customization point objects

The name ranges::crend denotes a customization point object, which is a const function object of a literalsemiregular class type. See CustomizationPointObject for details.

Example

Run this code

#include <algorithm>#include <iostream>#include <iterator>#include <vector>   int main(){int a[]{4, 6, -3, 9, 10};std::cout<<"Array backwards: ";namespace ranges = std::ranges;ranges::copy(ranges::rbegin(a), ranges::rend(a), std::ostream_iterator<int>(std::cout, " "));std::cout<<'\n';   std::cout<<"Vector backwards: ";std::vector v{4, 6, -3, 9, 10};ranges::copy(ranges::rbegin(v), ranges::rend(v), std::ostream_iterator<int>(std::cout, " "));std::cout<<'\n';}

Output:

Array backwards: 10 9 -3 6 4 Vector backwards: 10 9 -3 6 4

See also

ranges::rend (C++20)	returns a reverse end iterator to a range (customization point object)
rendcrend (C++14)	returns a reverse end iterator for a container or array (function template)