tests/ui/mut_reference.rs

   1
   2
   3
   4 #![allow(unused_variables, trivially_copy_pass_by_ref)]
   5
   6 fn takes_an_immutable_reference(a: &i32) {}
   7 fn takes_a_mutable_reference(a: &mut i32) {}
   8
   9 struct MyStruct;
  10
  11 impl MyStruct {
  12     fn takes_an_immutable_reference(&self, a: &i32) {
  13     }
  14
  15     fn takes_a_mutable_reference(&self, a: &mut i32) {
  16     }
  17 }
  18
  19 #[warn(unnecessary_mut_passed)]
  20 fn main() {
  21     // Functions
  22     takes_an_immutable_reference(&mut 42);
  23     let as_ptr: fn(&i32) = takes_an_immutable_reference;
  24     as_ptr(&mut 42);
  25
  26     // Methods
  27     let my_struct = MyStruct;
  28     my_struct.takes_an_immutable_reference(&mut 42);
  29
  30
  31     // No error
  32
  33     // Functions
  34     takes_an_immutable_reference(&42);
  35     let as_ptr: fn(&i32) = takes_an_immutable_reference;
  36     as_ptr(&42);
  37
  38     takes_a_mutable_reference(&mut 42);
  39     let as_ptr: fn(&mut i32) = takes_a_mutable_reference;
  40     as_ptr(&mut 42);
  41
  42     let a = &mut 42;
  43     takes_an_immutable_reference(a);
  44
  45     // Methods
  46     my_struct.takes_an_immutable_reference(&42);
  47     my_struct.takes_a_mutable_reference(&mut 42);
  48     my_struct.takes_an_immutable_reference(a);
  49 }