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std::list<T,Allocator>::rend, std::list<T,Allocator>::crend

From cppreference.com
< cpp‎ | container‎ | list
Revision as of 12:11, 4 May 2012 by P12bot (Talk | contribs)

 
 
 
 
reverse_iterator rend();
(1) (noexcept since C++11)
const_reverse_iterator rend() const;
(2) (noexcept since C++11)
const_reverse_iterator crend() const noexcept;
(3) (since C++11)

Returns a reverse iterator to the element following the last element of the reversed list. It corresponds to the element preceding the first element of the non-reversed list. This element acts as a placeholder, attempting to access it results in undefined behavior.

range-rbegin-rend.svg

Contents

Parameters

(none)

Return value

Reverse iterator to the element following the last element.

Complexity

Constant.

Notes

libc++ backports crend() to C++98 mode.

Example

#include <algorithm>
#include <iostream>
#include <numeric>
#include <string>
#include <list>
 
int main()
{
    std::list<int> nums{1, 2, 4, 8, 16};
    std::list<std::string> fruits{"orange", "apple", "raspberry"};
    std::list<char> empty;
 
    // Print list.
    std::for_each(nums.rbegin(), nums.rend(), [](const int n) { std::cout << n << ' '; });
    std::cout << '\n';
 
    // Sums all integers in the list nums (if any), printing only the result.
    std::cout << "Sum of nums: "
              << std::accumulate(nums.rbegin(), nums.rend(), 0) << '\n';
 
    // Prints the first fruit in the list fruits, checking if there is any.
    if (!fruits.empty())
        std::cout << "First fruit: " << *fruits.rbegin() << '\n';
 
    if (empty.rbegin() == empty.rend())
        std::cout << "list 'empty' is indeed empty.\n";
}

Output:

16 8 4 2 1
Sum of nums: 31
First fruit: raspberry
list 'empty' is indeed empty.

See also

returns a reverse iterator to the beginning
(public member function) [edit]
(C++14)
returns a reverse end iterator for a container or array
(function template) [edit]