Macro eprintln 

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

Prints to the standard error, with a newline.

Equivalent to the println! macro, except that output goes to io::stderr instead of io::stdout. See println! for example usage.

Use eprintln! only for error and progress messages. Use println! instead for the primary output of your program.

See the formatting documentation in std::fmt for details of the macro argument syntax.

Panics

Panics if writing to io::stderr fails.

Writing to non-blocking stderr can cause an error, which will lead this macro to panic.

Examples

eprintln!("Error: Could not complete task");