embedded_io/impls/
slice_mut.rs

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1use crate::{Error, ErrorKind, ErrorType, SliceWriteError, Write};
2use core::mem;
3
4impl Error for SliceWriteError {
5    fn kind(&self) -> ErrorKind {
6        match self {
7            SliceWriteError::Full => ErrorKind::WriteZero,
8        }
9    }
10}
11
12impl ErrorType for &mut [u8] {
13    type Error = SliceWriteError;
14}
15
16impl core::fmt::Display for SliceWriteError {
17    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
18        write!(f, "{self:?}")
19    }
20}
21
22#[cfg(feature = "std")]
23#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
24impl std::error::Error for SliceWriteError {}
25
26/// Write is implemented for `&mut [u8]` by copying into the slice, overwriting
27/// its data.
28///
29/// Note that writing updates the slice to point to the yet unwritten part.
30/// The slice will be empty when it has been completely overwritten.
31///
32/// If the number of bytes to be written exceeds the size of the slice, write operations will
33/// return short writes: ultimately, a `SliceWriteError::Full`.
34impl Write for &mut [u8] {
35    #[inline]
36    fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
37        let amt = core::cmp::min(buf.len(), self.len());
38        if !buf.is_empty() && amt == 0 {
39            return Err(SliceWriteError::Full);
40        }
41        let (a, b) = mem::take(self).split_at_mut(amt);
42        a.copy_from_slice(&buf[..amt]);
43        *self = b;
44        Ok(amt)
45    }
46
47    #[inline]
48    fn flush(&mut self) -> Result<(), Self::Error> {
49        Ok(())
50    }
51}
embedded_io/impls/slice_mut.rs

embedded_io/impls/
slice_mut.rs
