Function revm::precompile::primitives::bitvec::ptr::swap_nonoverlapping

source ·
pub unsafe fn swap_nonoverlapping<T1, T2, O1, O2>(
    one: BitPtr<Mut, T1, O1>,
    two: BitPtr<Mut, T2, O2>,
    count: usize
)
where O1: BitOrder, O2: BitOrder, T1: BitStore, T2: BitStore,
Expand description

§Many-Bit Swap

Exchanges the contents of two regions, which cannot overlap.

§Original

ptr::swap_nonoverlapping

§Safety

Both one and two must be:

  • correct BitPtr instances (well-aligned, non-null)
  • valid to read and write for the next count bits

Additionally, the ranges one .. one + count and two .. two + count must be entirely disjoint. They can be adjacent, but no bit can be in both.

§Examples

use bitvec::prelude::*;
use bitvec::ptr as bv_ptr;

let mut x = [0u8; 2];
let mut y = !0u16;
let x_ptr = BitPtr::<_, _, Msb0>::from_slice_mut(&mut x);
let y_ptr = BitPtr::<_, _, Lsb0>::from_mut(&mut y);

unsafe {
  bv_ptr::swap_nonoverlapping(x_ptr, y_ptr, 12);
}
assert_eq!(x, [!0, 0xF0]);
assert_eq!(y, 0xF0_00);