W3cubDocs

/C++

std::rend, std::crend

Defined in header `<array>`
Defined in header `<deque>`
Defined in header `<forward_list>`
Defined in header `<iterator>`
Defined in header `<list>`
Defined in header `<map>`
Defined in header `<regex>`
Defined in header `<set>`
Defined in header `<span>`		(since C++20)
Defined in header `<string>`
Defined in header `<string_view>`		(since C++17)
Defined in header `<unordered_map>`
Defined in header `<unordered_set>`
Defined in header `<vector>`
	(1)
template< class C > auto rend( C& c ) -> decltype(c.rend());		(since C++14) (until C++17)
template< class C > constexpr auto rend( C& c ) -> decltype(c.rend());		(since C++17)
	(1)
template< class C > auto rend( const C& c ) -> decltype(c.rend());		(since C++14) (until C++17)
template< class C > constexpr auto rend( const C& c ) -> decltype(c.rend());		(since C++17)
	(2)
template< class T, std::size_t N > std::reverse_iterator<T*> rend( T (&array)[N] );		(since C++14) (until C++17)
template< class T, std::size_t N > constexpr std::reverse_iterator<T*> rend( T (&array)[N] );		(since C++17)
	(3)
template< class T > std::reverse_iterator<const T*> rend( std::initializer_list<T> il );		(since C++14) (until C++17)
template< class T > constexpr std::reverse_iterator<const T*> rend( std::initializer_list<T> il );		(since C++17)
	(4)
template< class C > auto crend( const C& c ) -> decltype(std::rend(c));		(since C++14) (until C++17)
template< class C > constexpr auto crend( const C& c ) -> decltype(std::rend(c));		(since C++17)

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

1) Returns an iterator to the reverse-end of the possibly const-qualified container or view c.

2) Returns std::reverse_iterator<T*> to the reverse-end of the array array.

3) Returns std::reverse_iterator<const T*> to the reverse-end of the std::initializer_list il.

4) Returns an iterator to the reverse-end of the const-qualified container or view c.

Parameters

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

Return value

1) c.rend()

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

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

4) c.rend()

Exceptions

May throw implementation-defined exceptions.

Overloads

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

Overloads of rend found by argument-dependent lookup can be used to customize the behavior of std::ranges::rend and std::ranges::crend.

(since C++20)

Notes

The overload for std::initializer_list is necessary because it does not have a member function rend.

Example

#include <iostream>
#include <vector>
#include <iterator>
#include <algorithm>
 
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::cout << "\nstd::vector `v` backwards: ";
    std::vector<int> v = {4, 6, -3, 9, 10};
    std::copy(std::rbegin(v), std::rend(v), std::ostream_iterator<int>(std::cout, " "));
}

Output:

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

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