1 // Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution.
4 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
5 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
7 // option. This file may not be copied, modified, or distributed
8 // except according to those terms.
10 #![allow(unused_must_use)]
11 #![warn(clippy::write_literal)]
16 let mut v = Vec::new();
18 // these should be fine
19 write!(&mut v, "Hello");
20 writeln!(&mut v, "Hello");
22 writeln!(&mut v, "Hello {}", world);
23 writeln!(&mut v, "Hello {world}", world = world);
24 writeln!(&mut v, "3 in hex is {:X}", 3);
25 writeln!(&mut v, "2 + 1 = {:.4}", 3);
26 writeln!(&mut v, "2 + 1 = {:5.4}", 3);
27 writeln!(&mut v, "Debug test {:?}", "hello, world");
28 writeln!(&mut v, "{0:8} {1:>8}", "hello", "world");
29 writeln!(&mut v, "{1:8} {0:>8}", "hello", "world");
30 writeln!(&mut v, "{foo:8} {bar:>8}", foo = "hello", bar = "world");
31 writeln!(&mut v, "{bar:8} {foo:>8}", foo = "hello", bar = "world");
32 writeln!(&mut v, "{number:>width$}", number = 1, width = 6);
33 writeln!(&mut v, "{number:>0width$}", number = 1, width = 6);
35 // these should throw warnings
36 writeln!(&mut v, "{} of {:b} people know binary, the other half doesn't", 1, 2);
37 write!(&mut v, "Hello {}", "world");
38 writeln!(&mut v, "Hello {} {}", world, "world");
39 writeln!(&mut v, "Hello {}", "world");
40 writeln!(&mut v, "10 / 4 is {}", 2.5);
41 writeln!(&mut v, "2 + 1 = {}", 3);
43 // positional args don't change the fact
44 // that we're using a literal -- this should
46 writeln!(&mut v, "{0} {1}", "hello", "world");
47 writeln!(&mut v, "{1} {0}", "hello", "world");
49 // named args shouldn't change anything either
50 writeln!(&mut v, "{foo} {bar}", foo = "hello", bar = "world");
51 writeln!(&mut v, "{bar} {foo}", foo = "hello", bar = "world");