out 3.0.0

Provides functionality to get the n largest items from a &mut [T].
Documentation

out

Travis Crates.io Docs

Provides functionality to get the n largest items from a &mut [T].

let mut v = [-5, 4, 1, -3, 2];
let max = out::max(&mut v, 3);
assert_eq!(max, [1, 2, 4]);

This library can provide significant performance increase compared to sorting or converting to a heap when n is relatively small compared to the length of the slice.

Benchmarks

n = 100, len = 1_000_000:

openSUSE Tumbleweed, i7-5820K @ 3.30GHz, and 16GiB RAM:

test binary_heap   ... bench:   6,599,355 ns/iter (+/- 84,674)
test max           ... bench:     669,726 ns/iter (+/- 13,595)
test max_unstable  ... bench:     635,435 ns/iter (+/- 9,683)
test sort          ... bench:  62,585,547 ns/iter (+/- 1,361,258)
test sort_unstable ... bench:  34,595,265 ns/iter (+/- 739,255)

openSUSE Leap 15.0, i7-7700 @ 3.60GHz, and 32GiB RAM:

test binary_heap   ... bench:   5,521,422 ns/iter (+/- 124,780) 
test max           ... bench:     653,428 ns/iter (+/- 13,913) 
test max_unstable  ... bench:     524,200 ns/iter (+/- 61,033) 
test sort          ... bench:  41,428,917 ns/iter (+/- 486,681) 
test sort_unstable ... bench:  26,124,912 ns/iter (+/- 439,856)

Windows 10 Pro, i7-5820K @ 3.30GHz, and 16GiB RAM:

test binary_heap   ... bench:   8,550,850 ns/iter (+/- 1,118,958)
test max           ... bench:   2,282,062 ns/iter (+/- 564,063)
test max_unstable  ... bench:   2,179,817 ns/iter (+/- 741,751)
test sort          ... bench:  67,915,490 ns/iter (+/- 5,252,960)
test sort_unstable ... bench:  34,022,120 ns/iter (+/- 3,745,490)

License

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Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.