macro_rules! upgrade_error_to {
($i:expr, $ty:ty, $submac:ident!( $($args:tt)*) ) => { ... };
($i:expr, $ty:ty, $f:expr) => { ... };
($ty:ty, $e:expr) => { ... };
}
Expand description
Apply combinator, trying to “upgrade” error to next error type (using the Into
or From
traits).