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#[macro_export]
macro_rules! format_err {
($kind:expr, $msg:literal $(,)?) => {{
$crate::error::Error::message($kind, $msg)
}};
($kind:expr, $msg:expr $(,)?) => {{
$crate::error::Error::message($kind, $msg)
}};
($kind:expr, $msg:expr, $($arg:tt)*) => {{
$crate::error::Error::with_message($kind, || { format!($msg, $($arg)*) })
}};
}
#[macro_export]
macro_rules! ensure {
($cond:expr, $kind:expr, $msg:literal $(,)?) => {
if !$cond {
return ::std::result::Result::Err($crate::format_err!($kind, $msg));
}
};
($cond:expr, $kind:expr, dicate $msg:expr $(,)?) => {
if !$cond {
return ::std::result::Result::Err($crate::format_err!($kind, $msg));
}
};
($cond:expr, $kind:expr, dicate $msg:expr, $($arg:tt)*) => {
if !$cond {
return ::std::result::Result::Err($crate::format_err!($kind, $msg, $($arg)*));
}
};
}
#[macro_export]
macro_rules! ensure_eq {
($left:expr, $right:expr, $kind:expr, $msg:literal $(,)?) => {
$crate::ensure!($left == $right, $kind, $msg);
};
($left:expr, $right:expr, $kind:expr, dicate $msg:expr $(,)?) => {
$crate::ensure!($left == $right, $kind, $msg);
};
($left:expr, $right:expr, $kind:expr, dicate $msg:expr, $($arg:tt)*) => {
$crate::ensure!($left == $right, $kind, $msg, $($arg)*);
};
}
#[macro_export]
macro_rules! ensure_ne {
($left:expr, $right:expr, $kind:expr, $msg:literal $(,)?) => {
$crate::ensure!($left != $right, $kind, $msg);
};
($left:expr, $right:expr, $kind:expr, dicate $msg:expr $(,)?) => {
$crate::ensure!($left != $right, $kind, $msg);
};
($left:expr, $right:expr, $kind:expr, dicate $msg:expr, $($arg:tt)*) => {
$crate::ensure!($left != $right, $kind, $msg, $($arg)*);
};
}
#[cfg(test)]
mod tests {
use super::super::*;
#[derive(Debug, PartialEq, Copy, Clone)]
struct OperationError;
impl Display for OperationError {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "OperationError")
}
}
#[derive(thiserror::Error, Debug)]
enum IntermediateError {
#[error("second error")]
Io(#[from] std::io::Error),
}
#[test]
fn ensure_works() {
fn test_ensure(predicate: bool) -> crate::Result<()> {
ensure!(predicate, ErrorKind::Other, "predicate failed");
Ok(())
}
fn test_ensure_eq(item1: &str, item2: &str) -> crate::Result<()> {
ensure_eq!(item1, item2, ErrorKind::Other, "predicate failed");
Ok(())
}
fn test_ensure_ne(item1: &str, item2: &str) -> crate::Result<()> {
ensure_ne!(item1, item2, ErrorKind::Other, "predicate failed");
Ok(())
}
let err = test_ensure(false).unwrap_err();
assert_eq!(format!("{}", err), "predicate failed");
assert_eq!(err.kind(), &ErrorKind::Other);
assert!(test_ensure(true).is_ok());
let err = test_ensure_eq("foo", "bar").unwrap_err();
assert_eq!(format!("{}", err), "predicate failed");
assert_eq!(err.kind(), &ErrorKind::Other);
assert!(test_ensure_eq("foo", "foo").is_ok());
let err = test_ensure_ne("foo", "foo").unwrap_err();
assert_eq!(format!("{}", err), "predicate failed");
assert_eq!(err.kind(), &ErrorKind::Other);
assert!(test_ensure_ne("foo", "bar").is_ok());
}
}