rust/tests/ui/macros/rfc-2011-nicer-assert-messages/auxiliary/common.rs

26 lines
661 B
Rust

#[macro_export]
macro_rules! test {
(
let mut $elem_ident:ident = $elem_expr:expr;
[ $($assert:tt)* ] => $msg:literal
) => {
{
#[allow(unused_assignments, unused_mut, unused_variables)]
let rslt = std::panic::catch_unwind(|| {
let mut $elem_ident = $elem_expr;
assert!($($assert)*);
});
let err = rslt.unwrap_err();
if let Some(elem) = err.downcast_ref::<String>() {
assert_eq!(elem, &$msg);
}
else if let Some(elem) = err.downcast_ref::<&str>() {
assert_eq!(elem, &$msg);
}
else {
panic!("assert!( ... ) should return a string");
}
}
}
}