partition
partition slices in-place by a predicate
Rust has the Iterator::partition(_)
method, but this requires allocating two
Vec
s to hold the values. This has the benefit of preserving order, at the
cost of spending time and RAM to do the allocation, which also makes this API
unavailable on systems without an allocator.
This crate has a partition(..)
function to partition a mutable slice of
values by a predicate. It will swap around values to separate those the
predicate holds for and those it doesn't and return the two mutable sub-slices.
Warning
Note that since partition works by swapping values, the order of elements within the slice will not be preserved.
Example
let mut even_odd = ;
let = partition;
Performance
On a Core m3-6y30 with 4GB of RAM, I get the following benchmark results (in ns/iter):
Number of Elements | partition(&[T], _) |
Iter::partition(_) |
---|---|---|
10000 | 8,738 ± 665 | 101,625 ± 10,930 |
1000 | 896 ± 75 | 6,826 ± 760 |
100 | 118 ± 11 | 1,013 ± 116 |
10 | 14 ± 2 | 295 ± 93 |
1 | 4 ± 1 | 51 ± 7 |
So it's safe to say performance compares very favorably.
License
Licensed under either of at your discretion: