copy_backward

  #include <algorithm>
  iterator copy_backward( iterator start, iterator end, iterator dest );

copy_backward() is similar to (C++ Strings) copy(), in that both functions copy elements from start to end to dest. The copy_backward() function , however, starts depositing elements at dest and then works backwards, such that:

 *(dest-1) == *(end-1)
 *(dest-2) == *(end-2)
 *(dest-3) == *(end-3)
 ...
 *(dest-N) == *(end-N)          

The following code uses copy_backward() to copy 10 integers into the end of an empty vector:

 vector<int> from_vector;
 for( int i = 0; i < 10; i++ ) {
   from_vector.push_back( i );
 }              

 vector<int> to_vector(15);               

 copy_backward( from_vector.begin(), from_vector.end(), to_vector.end() );              

 cout << "to_vector contains: ";
 for( unsigned int i = 0; i < to_vector.size(); i++ ) {
   cout << to_vector[i] << " ";
 }
 cout << endl;            

The above code produces the following output:

 to_vector contains: 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9