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#![no_std]
#[macro_export]
macro_rules! try_or {
( $expr:expr , $or:expr ) => {{
match { $expr } {
Ok(res) => res,
Err(_) => { return { $or }; },
}
}}
}
#[macro_export]
macro_rules! try_or_else {
( $expr:expr , $or_fn:expr ) => {{
match { $expr } {
Ok(res) => res,
Err(err) => { return { $or_fn }(err); },
}
}}
}
#[macro_export]
macro_rules! try_opt_or {
( $expr:expr , $or:expr ) => {{
match { $expr } {
Some(res) => res,
None => return { $or },
}
}}
}
#[macro_export]
macro_rules! try_opt_or_else {
( $expr:expr , $or_fn:expr ) => {{
match { $expr } {
Some(res) => res,
None => return { $or_fn }(),
}
}}
}
#[cfg(test)]
mod tests {
#[test]
fn it_works() {
assert_eq!({ || try_or!("5".parse::<u32>(), 1) } (), 5);
assert_eq!({ || try_or!("a".parse::<u32>(), 1) } (), 1);
assert_eq!({ || try_or_else!("1".parse::<u32>(), |_| 5) } (), 1);
assert_eq!({ || try_or_else!("a".parse::<u32>(), |_| 5) } (), 5);
assert_eq!({ || try_opt_or!(Some(1), 2) } (), 1);
assert_eq!({ || try_opt_or!(None, 2) } (), 2);
assert_eq!({ || try_opt_or_else!(Some(1), || 2) } (), 1);
assert_eq!({ || try_opt_or_else!(None, || 2) } (), 2);
}
}