std::rend,std::crend

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Iterator library

Iterator concepts

indirectly_readable (C++20)
indirectly_writable (C++20)
weakly_incrementable (C++20)
incrementable (C++20)
is-integer-like is-signed-integer-like (C++20)(C++20)

sentinel_for (C++20)
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forward_iterator (C++20)
bidirectional_iterator (C++20)
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contiguous_iterator (C++20)

Iterator primitives

input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag

(C++20)

iter_value_titer_difference_titer_reference_titer_const_reference_titer_rvalue_reference_titer_common_reference_t

(C++20)(C++20)(C++20)(C++23)(C++20)(C++20)

iterator (deprecated in C++17)
iterator_traits
incrementable_traits (C++20)
indirectly_readable_traits (C++20)

Algorithm concepts and utilities

Indirect callable concepts

indirectly_unary_invocableindirectly_regular_unary_invocable

(C++20)(C++20)

indirect_unary_predicate (C++20)
indirect_binary_predicate (C++20)

indirect_equivalence_relation (C++20)
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Common algorithm requirements

indirectly_movable (C++20)
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indirectly_swappable (C++20)
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permutable (C++20)
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(C++20)

(C++20)

(C++26)

reverse_iterator
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move_iterator (C++11)
make_move_iterator (C++11)
default_sentinel_tdefault_sentinel (C++20)(C++20)
unreachable_sentinel_tunreachable_sentinel (C++20)(C++20)

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ranges::advance (C++20)
ranges::distance (C++20)
ranges::prev (C++20)
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Range access

begincbegin (C++11)(C++14)
rbegincrbegin (C++14)(C++14)

endcend (C++11)(C++14)
rendcrend (C++14)(C++14)

sizessize (C++17)(C++20)
empty (C++17)
data (C++17)

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Defined in header`<array>`
Defined in header`<deque>`
Defined in header`<flat_map>`
Defined in header`<flat_set>`
Defined in header`<forward_list>`
Defined in header`<inplace_vector>`
Defined in header`<iterator>`
Defined in header`<list>`
Defined in header`<map>`
Defined in header`<regex>`
Defined in header`<set>`
Defined in header`<span>`
Defined in header`<string>`
Defined in header`<string_view>`
Defined in header`<unordered_map>`
Defined in header`<unordered_set>`
Defined in header`<vector>`
template<class C> auto rend( C& c)-> decltype(c.rend());	(1)	(since C++14) (constexpr since C++17)
template<class C> auto rend(const C& c)-> decltype(c.rend());	(2)	(since C++14) (constexpr since C++17)
template<class T,std::size_t N> std::reverse_iterator<T*> rend( T(&array)[N]);	(3)	(since C++14) (constexpr since C++17)
template<class T> std::reverse_iterator<const T*> rend(std::initializer_list<T> il);	(4)	(since C++14) (constexpr since C++17)
template<class C> auto crend(const C& c)-> decltype(std::rend(c));	(5)	(since C++14) (constexpr since C++17)

Returns an iterator to the reverse-end of the given range.

1,2) Returnsc.rend(), which is typically an iterator one past the reverse-end of the sequence represented byc.

1) IfC is a standardContainer, returns aC::reverse_iterator object.

2) IfC is a standardContainer, returns aC::const_reverse_iterator object.

3) Returns anstd::reverse_iterator<T*> object to the reverse-end ofarray.

4) Returns anstd::reverse_iterator<const T*> object to the reverse-end ofil.

5) Returnsstd::end(c), withc always treated as const-qualified.

IfC is a standardContainer, returns aC::const_reverse_iterator object.

[edit]Parameters

c	-	a container or view with a`rend` member function
array	-	an array of arbitrary type
il	-	anstd::initializer_list

[edit]Return value

1,2)c.rend()

3)std::reverse_iterator<T*>(array)

4)std::reverse_iterator<const T*>(il.begin())

5)c.rend()

[edit]Exceptions

May throw implementation-defined exceptions.

[edit]Overloads

Custom overloads ofrend may be provided for classes and enumerations that do not expose a suitablerend() member function, yet can be iterated.

Overloads ofrend found byargument-dependent lookup can be used to customize the behavior ofstd::ranges::rend andstd::ranges::crend.

(since C++20)

[edit]Notes

The overload forstd::initializer_list is necessary because it does not have a member functionrend.

[edit]Example

Run this code

#include <algorithm>#include <iostream>#include <iterator>#include <vector> int main(){int a[]{4,6,-3,9,10};std::cout<<"C-style array `a` backwards: ";std::copy(std::rbegin(a), std::rend(a),std::ostream_iterator<int>(std::cout," ")); auto il={3,1,4};std::cout<<"\nstd::initializer_list `il` backwards: ";std::copy(std::rbegin(il), std::rend(il),std::ostream_iterator<int>(std::cout," ")); std::vector<int> v{4,6,-3,9,10};std::cout<<"\nstd::vector `v` backwards: ";std::copy(std::rbegin(v), std::rend(v),std::ostream_iterator<int>(std::cout," "));std::cout<<'\n';}

Output:

C-style array `a` backwards: 10 9 -3 6 4std::initializer_list `il` backwards: 4 1 3std::vector `v` backwards: 10 9 -3 6 4

[edit]See also

endcend (C++11)(C++14)	returns an iterator to the end of a container or array (function template)[edit]
rbegincrbegin (C++14)	returns a reverse iterator to the beginning of a container or array (function template)[edit]
begincbegin (C++11)(C++14)	returns an iterator to the beginning of a container or array (function template)[edit]
ranges::rend (C++20)	returns a reverse end iterator to a range (customization point object)[edit]
ranges::crend (C++20)	returns a reverse end iterator to a read-only range (customization point object)[edit]