tests/ui/traits/trait-upcasting/basic.rs

   1 // run-pass
   2
   3 #![feature(trait_upcasting)]
   4
   5 trait Foo: PartialEq<i32> + std::fmt::Debug + Send + Sync {
   6     fn a(&self) -> i32 {
   7         10
   8     }
   9
  10     fn z(&self) -> i32 {
  11         11
  12     }
  13
  14     fn y(&self) -> i32 {
  15         12
  16     }
  17 }
  18
  19 trait Bar: Foo {
  20     fn b(&self) -> i32 {
  21         20
  22     }
  23
  24     fn w(&self) -> i32 {
  25         21
  26     }
  27 }
  28
  29 trait Baz: Bar {
  30     fn c(&self) -> i32 {
  31         30
  32     }
  33 }
  34
  35 impl Foo for i32 {
  36     fn a(&self) -> i32 {
  37         100
  38     }
  39 }
  40
  41 impl Bar for i32 {
  42     fn b(&self) -> i32 {
  43         200
  44     }
  45 }
  46
  47 impl Baz for i32 {
  48     fn c(&self) -> i32 {
  49         300
  50     }
  51 }
  52
  53 fn main() {
  54     let baz: &dyn Baz = &1;
  55     let _: &dyn std::fmt::Debug = baz;
  56     assert_eq!(*baz, 1);
  57     assert_eq!(baz.a(), 100);
  58     assert_eq!(baz.b(), 200);
  59     assert_eq!(baz.c(), 300);
  60     assert_eq!(baz.z(), 11);
  61     assert_eq!(baz.y(), 12);
  62     assert_eq!(baz.w(), 21);
  63
  64     let bar: &dyn Bar = baz;
  65     let _: &dyn std::fmt::Debug = bar;
  66     assert_eq!(*bar, 1);
  67     assert_eq!(bar.a(), 100);
  68     assert_eq!(bar.b(), 200);
  69     assert_eq!(bar.z(), 11);
  70     assert_eq!(bar.y(), 12);
  71     assert_eq!(bar.w(), 21);
  72
  73     let foo: &dyn Foo = baz;
  74     let _: &dyn std::fmt::Debug = foo;
  75     assert_eq!(*foo, 1);
  76     assert_eq!(foo.a(), 100);
  77     assert_eq!(foo.z(), 11);
  78     assert_eq!(foo.y(), 12);
  79
  80     let foo: &dyn Foo = bar;
  81     let _: &dyn std::fmt::Debug = foo;
  82     assert_eq!(*foo, 1);
  83     assert_eq!(foo.a(), 100);
  84     assert_eq!(foo.z(), 11);
  85     assert_eq!(foo.y(), 12);
  86 }