# 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 `&mut` `Write`.

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());

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