Let's look at some code first
impl fmt::Write for ByteMutWriter<'_> {
fn write_str(&mut self, s: &str) -> fmt::Result {
let cap = self.capacity();
for (i, &b) in self.buf[self.cursor..cap]
.iter_mut()
.zip(s.as_bytes().iter())
{
*i = b;
}
self.cursor = usize::min(cap, self.cursor + s.as_bytes().len());
Ok(())
}
}This the meat and potatoes, although I haven't had time to optimise this for performance by any means. Astute readers are welcome to comment and share any improvements this can use.
We can also write this in a functional style. A mutable iterator is created into the shared slice
buf and then z ...(continued)
)
