std::writeln!

macro_rules! writeln {
    ( $ dst : expr , $ fmt : expr ) => { ... };
    (
$ dst : expr , $ fmt : expr , $ ( $ arg : tt ) * ) => { ... };
}

Use the format! syntax to write data into a buffer, appending a newline.

This macro is typically used with a buffer of &mutWrite.

See std::fmt for more information on format syntax.

Examples

fn main() { use std::io::Write; let mut w = Vec::new(); writeln!(&mut w, "test").unwrap(); writeln!(&mut w, "formatted {}", "arguments").unwrap(); assert_eq!(&w[..], "test\nformatted arguments\n".as_bytes()); }

use std::io::Write;

let mut w = Vec::new();
writeln!(&mut w, "test").unwrap();
writeln!(&mut w, "formatted {}", "arguments").unwrap();

assert_eq!(&w[..], "test\nformatted arguments\n".as_bytes());