1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Exercise the unused_mut attribute in some positive and negative cases
13 #![allow(unused_assignments)]
14 #![allow(unused_variables)]
21 let mut a = 3; //~ ERROR: variable does not need to be mutable
22 let mut a = 2; //~ ERROR: variable does not need to be mutable
23 let mut b = 3; //~ ERROR: variable does not need to be mutable
24 let mut a = vec![3]; //~ ERROR: variable does not need to be mutable
25 let (mut a, b) = (1, 2); //~ ERROR: variable does not need to be mutable
26 let mut a; //~ ERROR: variable does not need to be mutable
29 let mut b; //~ ERROR: variable does not need to be mutable
37 mut x => {} //~ ERROR: variable does not need to be mutable
40 (mut x, 1) | //~ ERROR: variable does not need to be mutable
47 let x = |mut y: isize| 10; //~ ERROR: variable does not need to be mutable
48 fn what(mut foo: isize) {} //~ ERROR: variable does not need to be mutable
50 let mut a = &mut 5; //~ ERROR: variable does not need to be mutable
54 let mut b = (&mut a,);
55 *b.0 = 4; //~^ ERROR: variable does not need to be mutable
57 let mut x = &mut 1; //~ ERROR: variable does not need to be mutable
63 fn mut_ref_arg(mut arg : &mut [u8]) -> &mut [u8] {
64 &mut arg[..] //~^ ERROR: variable does not need to be mutable
67 let mut v : &mut Vec<()> = &mut vec![]; //~ ERROR: variable does not need to be mutable
73 let mut a = Vec::new();
75 let mut a = Vec::new();
79 let (mut a, b) = (1, 2);
97 let x = |mut y: isize| y = 32;
98 fn nothing(mut foo: isize) { foo = 37; }
100 // leading underscore should avoid the warning, just like the
101 // unused variable lint.
102 let mut _allowed = 1;
105 fn callback<F>(f: F) where F: FnOnce() {}
107 // make sure the lint attribute can be turned off
109 fn foo(mut a: isize) {