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.
Panics if writing to io::stderr fails.
eprintln!("Error: Could not complete task");
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/macro.eprintln.html