Macro show_if_err 

macro_rules! show_if_err {
    ($res:expr) => { ... };
}

Display an error and set global exit code in error case.

Wraps around crate::show! and takes a crate::error::UResult instead of a crate::error::UError type. This macro invokes crate::show! if the crate::error::UResult is an Err-variant. This can be invoked directly on the result of a function call, like in the install utility:

show_if_err!(copy(sourcepath, &targetpath, b));

Examples

let is_ok = Ok(1);
// This does nothing at all
show_if_err!(is_ok);

let is_err = Err(USimpleError::new(1, "I'm an error").into());
// Calls `show!` on the contained USimpleError
show_if_err!(is_err);