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use crate::lib::fmt::{self, Write};
use crate::lib::str;
pub(super) struct Buf<'a> {
bytes: &'a mut [u8],
offset: usize,
}
impl<'a> Buf<'a> {
pub fn new(bytes: &'a mut [u8]) -> Self {
Buf { bytes, offset: 0 }
}
pub fn as_str(&self) -> &str {
let slice = &self.bytes[..self.offset];
unsafe { str::from_utf8_unchecked(slice) }
}
}
impl<'a> Write for Buf<'a> {
fn write_str(&mut self, s: &str) -> fmt::Result {
if self.offset + s.len() > self.bytes.len() {
Err(fmt::Error)
} else {
self.bytes[self.offset..self.offset + s.len()].copy_from_slice(s.as_bytes());
self.offset += s.len();
Ok(())
}
}
}