std::rend, std::crend - cppreference.com

template< class C >
auto rend( C& c ) noexcept(noexcept(c.rend()))
    -> decltype(c.rend());

template< class C >
auto rend( const C& c ) noexcept(noexcept(c.rend()))
    -> decltype(c.rend());

template< class T, std::size_t N >
std::reverse_iterator<T*> rend( T (&array)[N] ) noexcept;

template< class T >
std::reverse_iterator<const T*> rend( std::initializer_list<T> il ) noexcept;

template< class C >
auto crend( const C& c ) noexcept(noexcept(std::rend(c)))
    -> decltype(std::rend(c));

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

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

1) If C is a standard Container, returns a C::reverse_iterator object.

2) If C is a standard Container, returns a C::const_reverse_iterator object.

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

4) Returns an std::reverse_iterator<const T*> object to the reverse-end of il.

5) Returns std::end(c), with c always treated as const-qualified.

If C is a standard Container, returns a C::const_reverse_iterator object.

Parameters

Return value

1,2) c.rend()

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

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

5) std::rend(c)

Exceptions

1,2) What and when underlying c.rend() call throws.

5) What and when underlying std::rend(c) call throws.

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.

Notes

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

Example

#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';
}

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

Defect reports

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

See also