Function core::slice::sort::partition_at_index

pub fn partition_at_index<T, F>(
    v: &mut [T],
    index: usize,
    is_less: F
) -> (&mut [T], &mut T, &mut [T])where
    F: FnMut(&T, &T) -> bool,

🔬This is a nightly-only experimental API. (slice_internals)

Reorder the slice such that the element at index is at its final sorted position.