tests/ui/mut_reference.rs

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