src/tools/clippy/tests/ui/cmp_owned/asymmetric_partial_eq.fixed

   1 // run-rustfix
   2 #![allow(unused, clippy::redundant_clone, clippy::derive_partial_eq_without_eq)] // See #5700
   3
   4 // Define the types in each module to avoid trait impls leaking between modules.
   5 macro_rules! impl_types {
   6     () => {
   7         #[derive(PartialEq)]
   8         pub struct Owned;
   9
  10         pub struct Borrowed;
  11
  12         impl ToOwned for Borrowed {
  13             type Owned = Owned;
  14             fn to_owned(&self) -> Owned {
  15                 Owned {}
  16             }
  17         }
  18
  19         impl std::borrow::Borrow<Borrowed> for Owned {
  20             fn borrow(&self) -> &Borrowed {
  21                 static VALUE: Borrowed = Borrowed {};
  22                 &VALUE
  23             }
  24         }
  25     };
  26 }
  27
  28 // Only Borrowed == Owned is implemented
  29 mod borrowed_eq_owned {
  30     impl_types!();
  31
  32     impl PartialEq<Owned> for Borrowed {
  33         fn eq(&self, _: &Owned) -> bool {
  34             true
  35         }
  36     }
  37
  38     pub fn compare() {
  39         let owned = Owned {};
  40         let borrowed = Borrowed {};
  41
  42         if borrowed == owned {}
  43         if borrowed == owned {}
  44     }
  45 }
  46
  47 // Only Owned == Borrowed is implemented
  48 mod owned_eq_borrowed {
  49     impl_types!();
  50
  51     impl PartialEq<Borrowed> for Owned {
  52         fn eq(&self, _: &Borrowed) -> bool {
  53             true
  54         }
  55     }
  56
  57     fn compare() {
  58         let owned = Owned {};
  59         let borrowed = Borrowed {};
  60
  61         if owned == borrowed {}
  62         if owned == borrowed {}
  63     }
  64 }
  65
  66 mod issue_4874 {
  67     impl_types!();
  68
  69     // NOTE: PartialEq<Borrowed> for T can't be implemented due to the orphan rules
  70     impl<T> PartialEq<T> for Borrowed
  71     where
  72         T: AsRef<str> + ?Sized,
  73     {
  74         fn eq(&self, _: &T) -> bool {
  75             true
  76         }
  77     }
  78
  79     impl std::fmt::Display for Borrowed {
  80         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
  81             write!(f, "borrowed")
  82         }
  83     }
  84
  85     fn compare() {
  86         let borrowed = Borrowed {};
  87
  88         if borrowed == "Hi" {}
  89         if borrowed == "Hi" {}
  90     }
  91 }
  92
  93 fn main() {}