[swift-evolution] Proposal: Implement a rotate algorithm, equivalent to std::rotate() in C++

[Sergey Bolshedvorsky]

Hi everyone,

I’ve selected a ticket SR-125 as my first task (https://bugs.swift.org/browse/SR-125).

I would like to propose an implementation of this method in Swift stdlib.

std::rotate() method performs a left rotation on a range of elements.
C++ declaration is void rotate (ForwardIterator first, ForwardIterator middle, ForwardIterator last)
Specifically, it swaps the elements in the range [first, last) in such a way that the element middle becomes the first element of the new range and middle - 1 becomes the last element.
A precondition of this function is that [first, n_first) and [middle, last) are valid ranges.

What are your thoughts?

Sergey