Macro fatal::error

macro_rules! error {
    () => { ... };
    ($($arg:tt)*) => { ... };
}

Prints an error message to standard-error and exits with an error code.

Equivalent to fatal!, but prefixes the message (when present) with “Error: ”. If the color flag is set, will attempt to color the prefix in red.

User Experience

The message you write in the arguments is in the middle of a sentence, so you may or may not want to capitalize the beginning (unless it's a proper-noun, of course). Grammatically, either way is valid so it's just a matter of style.

E.g.

error!("bad input") // "Error: bad input"
error!("Bad input") // "Error: Bad input"