Function ptr_rotate_swap

unsafe fn ptr_rotate_swap<T>(left: usize, mid: *mut T, right: usize)

Algorithm 3 utilizes repeated swapping of min(left, right) elements.

///

left = 11, right = 4
[4 5 6 7 8 9 10 11 12 13 14 . 0 1 2 3]
                 ^  ^  ^  ^   ^ ^ ^ ^ swapping the right most elements with elements to the left
[4 5 6 7 8 9 10 . 0 1 2 3] 11 12 13 14
       ^ ^ ^  ^   ^ ^ ^ ^ swapping these
[4 5 6 . 0 1 2 3] 7 8 9 10 11 12 13 14
we cannot swap any more, but a smaller rotation problem is left to solve

when left < right the swapping happens from the left instead.

Safety

The specified range must be valid for reading and writing.