std::rend,std::crend (3) - Linux Manuals

std::rend,std::crend: std::rend,std::crend

NAME

std::rend,std::crend - std::rend,std::crend

Synopsis

Defined in header <iterator>
template< class C > (since C++14)
auto rend( C& c ) -> decltype(c.rend()); (until C++17)
template< class C > (since C++17)
constexpr auto rend( C& c ) -> decltype(c.rend());
template< class C > (since C++14)
auto rend( const C& c ) -> decltype(c.rend()); (until C++17)
template< class C > (since C++17)
constexpr auto rend( const C& c ) -> decltype(c.rend()); (1)
template< class T, size_t N > (since C++14)
reverse_iterator<T*> rend( T (&array)[N] ); (1) (until C++17)
template< class T, size_t N > (since C++17)
constexpr reverse_iterator<T*> rend( T (&array)[N] ); (2)
template< class C > (since C++14)
auto crend( const C& c ) -> decltype(std::rend(c)); (3) (until C++17)
template< class C > (since C++17)
constexpr auto crend( const C& c ) -> decltype(std::rend(c));

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.
2) Returns std::reverse_iterator<T*> to the reverse-end of the array array.
3) Returns a const-qualified iterator to the reverse-end of the container c.
 range-rbegin-rend.svg

Parameters

c - a container with a rend method
array - an array of arbitrary type

Return value

An iterator to the reverse-end of c or array

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>
, <span>
(since C++20), <string>
, <string_view>
(since C++17), <unordered_map>, <unordered_set>, and <vector>.

Overloads

Custom overloads of rend may be provided for classes that do not expose a suitable rend() member function, yet can be iterated. The following overload is already provided by the standard library:

rend(std::initializer_list) specializes std::rend
                            (function)
(C++14)

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