Macro die 

macro_rules! die {
    () => { ... };
    ($x:expr) => { ... };
    ($x:expr; $y:expr) => { ... };
    ($x:expr; $($y:expr),+) => { ... };
    ($($y:expr),+; $x:expr) => { ... };
    ($($arg:tt)*) => { ... };
}

Prints a message to stderr and terminates the current process with the specified exit code or 1 if no exit code is specified, by calling eprintln!() on all arguments followed by process::exit(exit_code)

Examples

Basic usage:

die!("argument to -e must be numeric"); // prints message to stderr then exits with code 1

With custom error code:

die!(2; "argument to -e must be numeric"); // prints message to stderr then exits with code 2

error code can go at the beginning or end, just separate with colon:

die!("argument to -e must be numeric"; 3); // prints message to stderr then exits with code 3

supports all the formatting eprintln! does:

die!("argument {} must be {}", "-e", 1; 4); // prints `argument -e must be 1` to stderr then exits with code 4

supports all the formatting eprintln! does without exit code too:

die!("argument {} must be {}", "-e", 1); // prints `argument -e must be 1` to stderr then exits with code 1

just exit with a code alone:

die!(2); // prints nothing, only exits with code 3

just exit:

die!(); // prints nothing, only exits with code 1