rust запись/чтение в бинарном виде

pub trait Write {
    fn write(&mut self, buf: &[u8]) -> Result<usize>;
    fn flush(&mut self) -> Result<()>;

    fn write_all(&mut self, buf: &[u8]) -> Result<()> { ... }
    fn write_fmt(&mut self, fmt: Arguments) -> Result<()> { ... }
    fn by_ref(&mut self) -> &mut Self where Self: Sized { ... }
    fn broadcast<W: Write>(self, other: W) -> Broadcast<Self, W> where Self: Sized { ... }
}

fn write(&mut self, buf: &[u8]) -> Result<usize>;

fn read(&mut self, buf: &mut [u8]) -> Result<usize>;

use std::slice;

// manifest a slice out of thin air!
let ptr = 0x1234 as *const usize;
let amt = 10;
unsafe {
    let slice = slice::from_raw_parts(ptr, amt);
}