std::rend, std::crend
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <iterator> | ||
| (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, size_t N >  reverse_iterator<T*> rend( T (&array)[N] ); | (since C++14) (until C++17) | |
| template< class T, size_t N >  constexpr reverse_iterator<T*> rend( T (&array)[N] ); | (since C++17) | |
| (3) | ||
| 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 container c or array array.
1) Returns a possibly const-qualified iterator to the reverse-end of the container 
c.3) Returns a const-qualified iterator to the reverse-end of the container 
c.
| Contents | 
[edit] Parameters
| c | - | a container with a rendmethod | 
| array | - | an array of arbitrary type | 
[edit] Return value
An iterator to the reverse-end of c or array
[edit] Notes
In addition to being included in <iterator>, std::rend and std::crend are guaranteed to become available if any of the following headers are included: <array>, <deque>, <forward_list>, <list>, <map>, <regex>, <set>, <string>, <string_view> (since C++17), <unordered_map>, <unordered_set>, and <vector>.
[edit] Overloads
Custom overloads of rbegin may be provided for classes that do not expose a suitable rbegin() member function, yet can be iterated. The following overload is already provided by the standard library:
| (C++14) | specializes std::rend (function) | 
[edit] Example
Run this code
#include <iostream> #include <vector> #include <iterator> #include <algorithm> int main() { int a[] = {4, 6, -3, 9, 10}; std::cout << "Array backwards: "; std::copy(std::rbegin(a), std::rend(a), std::ostream_iterator<int>(std::cout, " ")); std::cout << "\nVector 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:
Array backwards: 10 9 -3 6 4 Vector backwards: 10 9 -3 6 4
[edit] See also
| (C++11)(C++14) | returns an iterator to the end of a container or array (function) | 
| (C++14) | returns a reverse iterator to a container or array (function) | 
| (C++11)(C++14) | returns an iterator to the beginning of a container or array (function) | 


