src/test/ui/lint/lint-unnecessary-parens.rs

   1 #![deny(unused_parens)]
   2
   3 #[derive(Eq, PartialEq)]
   4 struct X { y: bool }
   5 impl X {
   6     fn foo(&self, conjunct: bool) -> bool { self.y && conjunct }
   7 }
   8
   9 fn foo() -> isize {
  10     return (1); //~ ERROR unnecessary parentheses around `return` value
  11 }
  12 fn bar(y: bool) -> X {
  13     return (X { y }); //~ ERROR unnecessary parentheses around `return` value
  14 }
  15
  16 fn unused_parens_around_return_type() -> (u32) { //~ ERROR unnecessary parentheses around type
  17     panic!()
  18 }
  19
  20 fn unused_parens_around_block_return() -> u32 {
  21     let foo = {
  22         (5) //~ ERROR unnecessary parentheses around block return value
  23     };
  24     (5) //~ ERROR unnecessary parentheses around block return value
  25 }
  26
  27 trait Trait {
  28     fn test(&self);
  29 }
  30
  31 fn passes_unused_parens_lint() -> &'static (dyn Trait) {
  32     panic!()
  33 }
  34
  35 macro_rules! baz {
  36     ($($foo:expr),+) => {
  37         ($($foo),*)
  38     }
  39 }
  40
  41 const CONST_ITEM: usize = (10); //~ ERROR unnecessary parentheses around assigned value
  42 static STATIC_ITEM: usize = (10); //~ ERROR unnecessary parentheses around assigned value
  43
  44 fn main() {
  45     foo();
  46     bar((true)); //~ ERROR unnecessary parentheses around function argument
  47
  48     if (true) {} //~ ERROR unnecessary parentheses around `if` condition
  49     while (true) {} //~ ERROR unnecessary parentheses around `while` condition
  50     //~^ WARN denote infinite loops with
  51     match (true) { //~ ERROR unnecessary parentheses around `match` scrutinee expression
  52         _ => {}
  53     }
  54     if let 1 = (1) {} //~ ERROR unnecessary parentheses around `let` scrutinee expression
  55     while let 1 = (2) {} //~ ERROR unnecessary parentheses around `let` scrutinee expression
  56     let v = X { y: false };
  57     // struct lits needs parens, so these shouldn't warn.
  58     if (v == X { y: true }) {}
  59     if (X { y: true } == v) {}
  60     if (X { y: false }.y) {}
  61
  62     while (X { y: false }.foo(true)) {}
  63     while (true | X { y: false }.y) {}
  64
  65     match (X { y: false }) {
  66         _ => {}
  67     }
  68
  69     X { y: false }.foo((true)); //~ ERROR unnecessary parentheses around method argument
  70
  71     let mut _a = (0); //~ ERROR unnecessary parentheses around assigned value
  72     _a = (0); //~ ERROR unnecessary parentheses around assigned value
  73     _a += (1); //~ ERROR unnecessary parentheses around assigned value
  74
  75     let _a = baz!(3, 4);
  76     let _b = baz!(3);
  77 }