macro_rules! writeln { ($dst:expr $(,)?) => { ... }; ($dst:expr, $($arg:tt)*) => { ... }; }
Available on
unstable
only.Expand description
Writes formatted data into a buffer, with a newline appended.
On all platforms, the newline is the LINE FEED character (\n
/U+000A
) alone
(no additional CARRIAGE RETURN (\r
/U+000D
).
For more information, see write!
. For information on the format string syntax, see
std::fmt
.
§Examples
use std::io::{Write, Result};
fn main() -> Result<()> {
let mut w = Vec::new();
writeln!(&mut w)?;
writeln!(&mut w, "test")?;
writeln!(&mut w, "formatted {}", "arguments")?;
assert_eq!(&w[..], "\ntest\nformatted arguments\n".as_bytes());
Ok(())
}