[section:rotate rotate]

[heading Prototype]

``
template<class ForwardRange>
ForwardRange& rotate(ForwardRange& rng,
                     typename range_iterator<ForwardRange>::type middle);

template<class ForwardRange>
const ForwardRange& rotate(const ForwardRange& rng,
                           typename range_iterator<const ForwardRange>::type middle);
``

[heading Description]

`rotate` rotates the elements in a range. It exchanges the two ranges `[begin(rng), middle)` and `[middle, end(rng))`. Returns a reference to `rng`.

[heading Definition]

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

[heading Requirements]

* `ForwardRange` is a model of the __forward_range__ Concept.
* `ForwardRange` is mutable.

[heading Precondition:]

* `[begin(rng), middle)` is a valid range.
* `[middle, end(rng))` is a valid range.

[heading Complexity]

Linear. At most `distance(rng)` swaps are performed.

[endsect]