Description : The function returns an const_reverse_iterator pointing to the last element in the container (i.e., its reverse beginning). The iterator points to past-the-end element of the vector.
Example:
// Demonstrates cbegin()
#include <iostream>
#include <vector>
int main ()
{
std::vector<int> myvector = {1,2,3,4,5};
std::cout << "myvector backwards:";
for (auto rit = myvector.crbegin(); rit != myvector.crend(); ++rit)
std::cout << ' ' << *rit;
std::cout << '\n';
return 0;
}