rust/tests/ui/traits/inheritance/cast.rs
2024-02-16 20:02:50 +00:00

34 lines
522 B
Rust

//@ run-pass
#![allow(dead_code)]
// Testing that supertrait methods can be called on subtrait object types
trait Foo {
fn f(&self) -> isize;
}
trait Bar : Foo {
fn g(&self) -> isize;
}
struct A {
x: isize
}
impl Foo for A {
fn f(&self) -> isize { 10 }
}
impl Bar for A {
fn g(&self) -> isize { 20 }
}
pub fn main() {
let a = &A { x: 3 };
let afoo = a as &dyn Foo;
let abar = a as &dyn Bar;
assert_eq!(afoo.f(), 10);
assert_eq!(abar.g(), 20);
assert_eq!(abar.f(), 10);
}