NAME¶

std::list::rbegin,std::list::crbegin - std::list::rbegin,std::list::crbegin

Synopsis¶

reverse_iterator rbegin(); (1) (noexcept since C++11)
const_reverse_iterator rbegin() const; (2) (noexcept since C++11)
const_reverse_iterator crbegin() const noexcept; (3) (since C++11)

Returns a reverse iterator to the first element of the reversed list. It corresponds
to the last element of the non-reversed list. If the list is empty, the returned
iterator is equal to rend().

range-rbegin-rend.svg

Parameters¶

(none)

Return value¶

Reverse iterator to the first element.

Complexity¶

Constant.

Notes¶

The underlying iterator of the returned reverse iterator is the end iterator. Hence
the returned iterator is invalidated if and when the end iterator is invalidated.

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

Example¶

// Run this code

#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¶

rend returns a reverse iterator to the end
crend (public member function)
(C++11)
rbegin returns a reverse iterator to the beginning of a container or array
crbegin (function template)
(C++14)