range in alloc::slice - Rust (original) (raw)

Function range

pub const fn range<R>(range: R, bounds: RangeTo<usize>) -> Range<usize>

where
    R: RangeBounds<usize>,

🔬This is a nightly-only experimental API. (slice_range #76393)

Expand description

Performs bounds checking of a range.

This method is similar to Index::index for slices, but it returns aRange equivalent to range. You can use this method to turn any range into start and end values.

bounds is the range of the slice to use for bounds checking. It should be a RangeTo range that ends at the length of the slice.

The returned Range is safe to pass to slice::get_unchecked andslice::get_unchecked_mut for slices with the given range.

§Panics

Panics if range would be out of bounds.

§Examples

#![feature(slice_range)]

use std::slice;

let v = [10, 40, 30];
assert_eq!(1..2, slice::range(1..2, ..v.len()));
assert_eq!(0..2, slice::range(..2, ..v.len()));
assert_eq!(1..3, slice::range(1.., ..v.len()));

Panics when Index::index would panic:

ⓘ

#![feature(slice_range)]

use std::slice;

let _ = slice::range(2..1, ..3);

ⓘ

#![feature(slice_range)]

use std::slice;

let _ = slice::range(1..4, ..3);

ⓘ

#![feature(slice_range)]

use std::slice;

let _ = slice::range(1..=usize::MAX, ..3);