public member function
<vector>

std::vector::rbegin

      reverse_iterator rbegin();
const_reverse_iterator rbegin() const;

      reverse_iterator rbegin() noexcept;
const_reverse_iterator rbegin() const noexcept;
Return reverse iterator to reverse beginning
Returns a reverse iterator pointing to the last element in the vector (i.e., its reverse beginning).

Reverse iterators iterate backwards: increasing them moves them towards the beginning of the container.

rbegin points to the element right before the one that would be pointed to by member end.

Notice that unlike member vector::back, which returns a reference to this same element, this function returns a reverse random access iterator.

Parameters

none

Return Value

A reverse iterator to the reverse beginning of the sequence container.

If the vector object is const-qualified, the function returns a const_reverse_iterator. Otherwise, it returns a reverse_iterator.

Member types reverse_iterator and const_reverse_iterator are reverse random access iterator types (pointing to an element and to a const element, respectively). See vector member types.

Example

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// vector::rbegin/rend
#include <iostream>
#include <vector>

int main ()
{
  std::vector<int> myvector (5);  // 5 default-constructed ints

  int i=0;

  std::vector<int>::reverse_iterator rit = myvector.rbegin();
  for (; rit!= myvector.rend(); ++rit)
    *rit = ++i;

  std::cout << "myvector contains:";
  for (std::vector<int>::iterator it = myvector.begin(); it != myvector.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}


Output:
myvector contains: 5 4 3 2 1

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed (neither the const nor the non-const versions modify the container).
No contained elements are accessed by the call, but the iterator returned can be used to access or modify elements. Concurrently accessing or modifying different elements is safe.

Exception safety

No-throw guarantee: this member function never throws exceptions.
The copy construction or assignment of the returned iterator is also guaranteed to never throw.

See also

vector::back
Access last element (public member function )
vector::rend
Return reverse iterator to reverse end (public member function )
vector::begin
Return iterator to beginning (public member function )
vector::end
Return iterator to end (public member function )

C++