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