std::copy_backward

 

C++

Language

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Algorithm library

Functions
Non-modifying sequence operations
all_of any_of none_of (C++11) (C++11) (C++11) for_each count count_if mismatch equal	find find_if find_if_not (C++11) find_end find_first_of adjacent_find search search_n
Modifying sequence operations
copy copy_if (C++11) copy_n (C++11) copy_backward move (C++11) move_backward (C++11) fill fill_n transform generate generate_n remove remove_if remove_copy remove_copy_if	replace replace_if replace_copy replace_copy_if swap swap_ranges iter_swap reverse reverse_copy rotate rotate_copy random_shuffle shuffle   (C++11) unique unique_copy
Partitioning operations
is_partitioned (C++11) partition partition_copy (C++11)	stable_partition partition_point (C++11)
Sorting operations (on sorted ranges)
is_sorted (C++11) is_sorted_until (C++11) sort	partial_sort partial_sort_copy stable_sort nth_element
Binary search operations (on sorted ranges)
lower_bound upper_bound	binary_search equal_range
Set operations (on sorted ranges)
merge inplace_merge includes	set_difference set_intersection set_symmetric_difference set_union
Heap operations
is_heap is_heap_until (C++11) make_heap	push_heap pop_heap sort_heap
Minimum/maximum operations
max max_element min min_element minmax (C++11) minmax_element (C++11)	lexicographical_compare is_permutation (C++11) next_permutation prev_permutation
Numeric operations
iota (C++11) accumulate inner_product	adjacent_difference partial_sum
C library
qsort	bsearch

 

Defined in header <algorithm>
template< class BidirectionalIterator1, class BidirectionalIterator2 > BidirectionalIterator2 copy_backward( BidirectionalIterator1 first,                                       BidirectionalIterator1 last,                                       BidirectionalIterator2 d_last );

Copies the elements from the range, defined by [first, last), to another range ending at d_last. The elements are copied in reverse order (the last element is copied first), but their relative order is preserved.

Parameters

first, last	-	the range of the elements to copy
d_last	-	end of the destination range. If d_last is within [first, last), std::copy must be used instead of std::copy_backward.

Return value

iterator to the last element copied.

Complexity

Exactly last - first assignments.

Possible implementation

template< class BidirectionalIterator1, class BidirectionalIterator2 > BidirectionalIterator2 copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last, BidirectionalIterator2 d_last) { while (first != last) { *(--d_last) = *(--last); } return d_last; }

Example

#include <algorithm>
#include <iostream>
 
int main()
{
    std::vector<int> from_vector;
    for (int i = 0; i < 10; i++) {
        from_vector.push_back(i);
    }
 
    std::vector<int> to_vector(15);
 
    std::copy_backward(from_vector.begin(), from_vector.end(), to_vector.end());
 
    std::cout << "to_vector contains: ";
    for (unsigned int i = 0; i < to_vector.size(); i++) {
        std::cout << to_vector[i] << " ";
    }
 }

Output:

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

See also

copy copy_if (C++11)	copies a range of elements to a new location (function template)