src/test/ui/lint/dead-code/lint-dead-code-4.rs

   1 #![allow(unused_variables)]
   2 #![allow(non_camel_case_types)]
   3 #![deny(dead_code)]
   4
   5 struct Foo {
   6     x: usize,
   7     b: bool, //~ ERROR: field is never read
   8 }
   9
  10 fn field_read(f: Foo) -> usize {
  11     f.x.pow(2)
  12 }
  13
  14 enum XYZ {
  15     X, //~ ERROR variant is never constructed
  16     Y { //~ ERROR variant is never constructed
  17         a: String,
  18         b: i32,
  19         c: i32,
  20     },
  21     Z
  22 }
  23
  24 enum ABC { //~ ERROR enum is never used
  25     A,
  26     B {
  27         a: String,
  28         b: i32,
  29         c: i32,
  30     },
  31     C
  32 }
  33
  34 // ensure struct variants get warning for their fields
  35 enum IJK {
  36     I, //~ ERROR variant is never constructed
  37     J {
  38         a: String,
  39         b: i32, //~ ERROR field is never read
  40         c: i32, //~ ERROR field is never read
  41     },
  42     K //~ ERROR variant is never constructed
  43
  44 }
  45
  46 fn struct_variant_partial_use(b: IJK) -> String {
  47     match b {
  48         IJK::J { a, b: _, .. } => a,
  49         _ => "".to_string()
  50     }
  51 }
  52
  53 fn field_match_in_patterns(b: XYZ) -> String {
  54     match b {
  55         XYZ::Y { a, b: _, .. } => a,
  56         _ => "".to_string()
  57     }
  58 }
  59
  60 struct Bar {
  61     x: usize, //~ ERROR: field is never read
  62     b: bool,
  63     c: bool, //~ ERROR: field is never read
  64     _guard: ()
  65 }
  66
  67 #[repr(C)]
  68 struct Baz {
  69     x: u32,
  70 }
  71
  72 fn field_match_in_let(f: Bar) -> bool {
  73     let Bar { b, c: _, .. } = f;
  74     b
  75 }
  76
  77 fn main() {
  78     field_read(Foo { x: 1, b: false });
  79     field_match_in_patterns(XYZ::Z);
  80     struct_variant_partial_use(IJK::J { a: "".into(), b: 1, c: -1 });
  81     field_match_in_let(Bar { x: 42, b: true, c: false, _guard: () });
  82     let _ = Baz { x: 0 };
  83 }