Trait ParallelDrainRange

pub trait ParallelDrainRange<Idx = usize> {
    type Iter: ParallelIterator<Item = Self::Item>;
    type Item: Send;

    // Required method
    fn par_drain<R: RangeBounds<Idx>>(self, range: R) -> Self::Iter;
}

ParallelDrainRange creates a parallel iterator that moves a range of items from a collection while retaining the original capacity.

Types which are not indexable may implement ParallelDrainFull instead.

Required Associated Types

type Iter: ParallelIterator<Item = Self::Item>

The draining parallel iterator type that will be created.

type Item: Send

The type of item that the parallel iterator will produce. This is usually the same as IntoParallelIterator::Item.

Required Methods

fn par_drain<R: RangeBounds<Idx>>(self, range: R) -> Self::Iter

Returns a draining parallel iterator over a range of the collection.

When the iterator is dropped, all items in the range are removed, even if the iterator was not fully consumed. If the iterator is leaked, for example using std::mem::forget, it is unspecified how many items are removed.

Examples

use rayon::prelude::*;

let squares: Vec<i32> = (0..10).map(|x| x * x).collect();

println!("RangeFull");
let mut vec = squares.clone();
assert!(vec.par_drain(..)
           .eq(squares.par_iter().copied()));
assert!(vec.is_empty());
assert!(vec.capacity() >= squares.len());

println!("RangeFrom");
let mut vec = squares.clone();
assert!(vec.par_drain(5..)
           .eq(squares[5..].par_iter().copied()));
assert_eq!(&vec[..], &squares[..5]);
assert!(vec.capacity() >= squares.len());

println!("RangeTo");
let mut vec = squares.clone();
assert!(vec.par_drain(..5)
           .eq(squares[..5].par_iter().copied()));
assert_eq!(&vec[..], &squares[5..]);
assert!(vec.capacity() >= squares.len());

println!("RangeToInclusive");
let mut vec = squares.clone();
assert!(vec.par_drain(..=5)
           .eq(squares[..=5].par_iter().copied()));
assert_eq!(&vec[..], &squares[6..]);
assert!(vec.capacity() >= squares.len());

println!("Range");
let mut vec = squares.clone();
assert!(vec.par_drain(3..7)
           .eq(squares[3..7].par_iter().copied()));
assert_eq!(&vec[..3], &squares[..3]);
assert_eq!(&vec[3..], &squares[7..]);
assert!(vec.capacity() >= squares.len());

println!("RangeInclusive");
let mut vec = squares.clone();
assert!(vec.par_drain(3..=7)
           .eq(squares[3..=7].par_iter().copied()));
assert_eq!(&vec[..3], &squares[..3]);
assert_eq!(&vec[3..], &squares[8..]);
assert!(vec.capacity() >= squares.len());

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'a> ParallelDrainRange for &'a mut String

type Iter = Drain<'a>

type Item = char

fn par_drain<R: RangeBounds<usize>>(self, range: R) -> Self::Iter

impl<'a, T: Send> ParallelDrainRange for &'a mut VecDeque<T>

type Iter = Drain<'a, T>

type Item = T

fn par_drain<R: RangeBounds<usize>>(self, range: R) -> Self::Iter

impl<'data, T: Send> ParallelDrainRange for &'data mut Vec<T>

type Iter = Drain<'data, T>

type Item = T

fn par_drain<R: RangeBounds<usize>>(self, range: R) -> Self::Iter

Implementors