# Function alloc::slice::try_range

source ·

    pub fn try_range<R>(range: R, bounds: RangeTo<usize>) -> Option<Range<usize>>where
        R: RangeBounds<usize>,

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

Performs bounds-checking of a range without panicking.

This is a version of `range()` that returns `None` instead of panicking.

## §Examples

    #![feature(slice_range)]

    use std::slice;

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

Run

Returns `None` when `Index::index` would panic:

    #![feature(slice_range)]

    use std::slice;

    assert_eq!(None, slice::try_range(2..1, ..3));
    assert_eq!(None, slice::try_range(1..4, ..3));
    assert_eq!(None, slice::try_range(1..=usize::MAX, ..3));

Run