tcio 0.1.4

Collection of utility types.
Documentation 
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//! Formatting utilities.

/// Lossy [`Debug`] and [`Display`] implementation of `[u8]`.
///
/// # Examples
///
/// ```
/// use tcio::fmt::lossy;
///
/// let mut bytes = Vec::from(&b"Content-Type"[..]);
/// bytes.push(0x12);
///
/// // will print `Content-Type\x12`
/// println!("Bytes: {}", lossy(&bytes));
///
/// // will print `b"Content-Type\x12"`
/// println!("Bytes: {:?}", lossy(&bytes));
///
/// # assert_eq!(&format!("{}", lossy(&bytes)), &r#"Content-Type\x12"#[..]);
/// # assert_eq!(&format!("{:?}", lossy(&bytes)), &r#"b"Content-Type\x12""#[..]);
/// ```
///
/// [`Debug`]: std::fmt::Debug
/// [`Display`]: std::fmt::Display
#[inline]
pub fn lossy<B: AsRef<[u8]>>(buf: &B) -> LossyFmt<'_> {
    LossyFmt(buf.as_ref())
}

/// Return type of [`lossy`].
pub struct LossyFmt<'a>(&'a [u8]);

impl std::fmt::Display for LossyFmt<'_> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        for &b in self.0 {
            if b.is_ascii_graphic() || b.is_ascii_whitespace() {
                write!(f, "{}", b as char)?;
            } else {
                write!(f, "\\x{b:x}")?;
            }
        }
        Ok(())
    }
}

impl std::fmt::Debug for LossyFmt<'_> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "b\"{self}\"")
    }
}