# std::rend, std::crend

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< cpp‎ | iterator

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

Run this code

    #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

### See also

end cend (C++11)(C++14) | returns an iterator to the end of a container or array (function template)
rbegin crbegin (C++14) | returns a reverse iterator to the beginning of a container or array (function template)
begin cbegin (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)

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