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use std::{error::Error, fmt};
use derive_more::Deref;
#[derive(Debug, Clone, Copy, Default, Hash, PartialEq, Eq, Deref)]
#[cfg_attr(any(target_arch = "x86_64", target_arch = "aarch64"), repr(align(128)))]
#[cfg_attr(
not(any(target_arch = "x86_64", target_arch = "aarch64")),
repr(align(64))
)]
pub struct CachePadded<T>(pub T);
#[macro_export]
macro_rules! ward {
($o:expr) => (ward!($o, else { return; }));
($o:expr, else $body:block) => { if let Some(x) = $o { x } else { $body }; };
($o:expr, $early:stmt) => (ward!($o, else { $early }));
}
pub struct ErrorChain<'a>(pub &'a dyn Error);
impl fmt::Display for ErrorChain<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.0)?;
let mut cursor = self.0;
while let Some(err) = cursor.source() {
write!(f, ": {}", err)?;
cursor = err;
}
Ok(())
}
}
#[test]
fn trivial_error_chain() {
let error = anyhow::anyhow!("oops");
assert_eq!(format!("{}", ErrorChain(&*error)), "oops");
}
#[test]
fn error_chain() {
let innermost = anyhow::anyhow!("innermost");
let inner = innermost.context("inner");
let outer = inner.context("outer");
assert_eq!(
format!("{}", ErrorChain(&*outer)),
"outer: inner: innermost"
);
}