Function core::slice::sort::insert_head

unsafe fn insert_head<T, F>(v: &mut [T], is_less: &mut F)where
    F: FnMut(&T, &T) -> bool,

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

Inserts v[0] into pre-sorted sequence v[1..] so that whole v[..] becomes sorted.

This is the integral subroutine of insertion sort.