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std::rbegin

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< cpp‎ | iterator
Revision as of 12:31, 9 September 2013 by Cubbi (Talk | contribs)

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

Returns an iterator to the reverse-beginning of the given container c or array array.

1) Returns a possibly const-qualified iterator to the reverse-beginning of the container c.
2) Returns std::reverse_iterator<T*> to the reverse-beginning of the array array.
3) Returns a const-qualified iterator to the reverse-beginning of the container c.

range-rbegin-rend.svg

Contents

Parameters

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

Return value

An iterator to the reverse-beginning of c or array

Notes

In addition to being included in <iterator>, std::rbegin is guaranteed to become available if any of the following headers are included: <array>, <deque>, <forward_list>, <list>, <map>, <regex>, <set>, <string>, <unordered_map>, <unordered_set>, and <vector>.

Specializations

Custom specializations of std::rbegin may be provided for classes that do not expose a suitable rbegin() member function, yet can be iterated. The following specializations are already provided by the standard library:

specializes std::rbegin
(function) [edit]

Example

#include <iostream>
#include <vector>
#include <iterator>
 
int main() 
{
    std::vector<int> v = { 3, 1, 4 };
    auto vi = std::rbegin(v);
    std::cout << *vi << '\n'; 
 
    int a[] = { -5, 10, 15 };
    auto ai = std::rbegin(a);
    std::cout << *ai << '\n';
}

Output:

4
-5

See also

(C++14)
returns a reverse end iterator for a container or array
(function) [edit]