// run-pass #![feature(trait_upcasting)] trait Foo: PartialEq + std::fmt::Debug + Send + Sync { fn a(&self) -> i32 { 10 } fn z(&self) -> i32 { 11 } fn y(&self) -> i32 { 12 } } trait Bar: Foo { fn b(&self) -> i32 { 20 } fn w(&self) -> i32 { 21 } } trait Baz: Bar { fn c(&self) -> i32 { 30 } } impl Foo for i32 { fn a(&self) -> i32 { 100 } } impl Bar for i32 { fn b(&self) -> i32 { 200 } } impl Baz for i32 { fn c(&self) -> i32 { 300 } } fn main() { let baz: &dyn Baz = &1; let _: &dyn std::fmt::Debug = baz; assert_eq!(*baz, 1); assert_eq!(baz.a(), 100); assert_eq!(baz.b(), 200); assert_eq!(baz.c(), 300); assert_eq!(baz.z(), 11); assert_eq!(baz.y(), 12); assert_eq!(baz.w(), 21); let bar: &dyn Bar = baz; let _: &dyn std::fmt::Debug = bar; assert_eq!(*bar, 1); assert_eq!(bar.a(), 100); assert_eq!(bar.b(), 200); assert_eq!(bar.z(), 11); assert_eq!(bar.y(), 12); assert_eq!(bar.w(), 21); let foo: &dyn Foo = baz; let _: &dyn std::fmt::Debug = foo; assert_eq!(*foo, 1); assert_eq!(foo.a(), 100); assert_eq!(foo.z(), 11); assert_eq!(foo.y(), 12); let foo: &dyn Foo = bar; let _: &dyn std::fmt::Debug = foo; assert_eq!(*foo, 1); assert_eq!(foo.a(), 100); assert_eq!(foo.z(), 11); assert_eq!(foo.y(), 12); }