Method take

base64ct/src/decoder.rs:318–329

Take a specified number of bytes from the buffer. Returns as many bytes as possible, or an empty slice if the buffer has already been read to completion.

(&mut self, mut nbytes: usize)

    /// Returns as many bytes as possible, or an empty slice if the buffer has
    /// already been read to completion.
    fn take(&mut self, mut nbytes: usize) -> Result<&[u8], Error> {
        debug_assert!(self.position <= self.length);
        let start_pos = self.position;
        let remaining_len = self.length.checked_sub(start_pos).ok_or(InvalidLength)?;

        if nbytes > remaining_len {
            nbytes = remaining_len;
        }

        self.position = self.position.checked_add(nbytes).ok_or(InvalidLength)?;
        Ok(&self.decoded[start_pos..][..nbytes])
    }

    /// Have all of the bytes in this buffer been consumed?
    fn is_empty(&self) -> bool {