copy_backward

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##### copy_backward

###### Prototype

    template<class BidirectionalRange, class BidirectionalOutputIterator>
        BidirectionalOutputIterator
            copy_backward(const BidirectionalRange& source_rng,
                          BidirectionalOutputIterator out_it);

###### Description

`copy_backward` copies all elements from `source_rng` to the range `[out_it - distance(source_rng), out_it)`.

The values are copied in reverse order. The return value is `out_it - distance(source_rng)`.

Note well that unlike all other standard algorithms `out_it` denotes the end of the output sequence.

###### Definition

Defined in the header file `boost/range/algorithm/copy_backward.hpp`

###### Requirements

- `BidirectionalRange` is a model of Bidirectional Range Concept.
- `OutputIterator` is a model of the `OutputIteratorConcept`.
- The `value_type` of Bidirectional Range Concept is convertible to a type in `OutputIterator`'s set of value types.

###### Precondition:

- `out_it` is not an iterator within the `source_rng`.
- `[out_it, out_it + distance(source_rng))` is a valid range.

###### Complexity

Linear. Exactly `distance(source_rng)` assignments are performed.