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Generate permutations of a slice in a memory-efficient and deterministic manner, using Heap’s algorithm.

For instance, printing all the permutations of the sequence [“red”, “green”, “blue”]:

use permute::permutations_of;

for permutation in permutations_of(&["red", "green", "blue"]) {
    for element in permutation {
        print!("{}, ", element);

Based on the ordering provided by Heap’s algorithm, it’s guaranteed that this program will produce:

red, green, blue,
green, red, blue,
blue, red, green,
red, blue, green,
green, blue, red,
blue, green, red,

This crate also provides the ArbitraryTandemControlIter, which allows iterating over a slice using a slice of indices - that’s how Heap’s algorithm is implemented here.


An iterator over a slice that uses another iterator to control the next element in the sequence, in any arbitrary order, without copying.


Produce an iterator over iterators, each one of which yields one permutation of the provided slice. No copying of elements of the slice occurs.

Generate permutations of a given Vec by copying.