Function bitvec::ptr::write_bits

pub unsafe fn write_bits<T, O>(
    dst: BitPtr<Mut, T, O>,
    value: bool,
    count: usize
)
where
    T: BitStore,
    O: BitOrder,

Bit-wise memset

This fills a region of memory with a bit value. It is equivalent to using memset with only !0 or 0, masked appropriately for the region edges.

Original

ptr::write_bytes

Safety

Because this performs a dereference of memory, it inherits the original ptr::write_bytes’ requirements:

• dst must be valid to write
• dst must be properly aligned. This is an invariant of the BitPtr type as well as of the memory access.

Additionally, dst must point to an initialized value of T. Integers cannot be initialized one bit at a time.

Behavior

This function does not specify an implementation. You should assume the worst case (O(n) read/modify/write of each bit). The BitSlice::fill method will have equal or better performance.

Examples

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

let mut data = 0u8;
let ptr = BitPtr::<_, _, Lsb0>::from_mut(&mut data);
unsafe {
  bv_ptr::write_bits(ptr.add(1), true, 5);
}
assert_eq!(data, 0b0011_1110);