| // run-pass |
| // Test equality constraints on associated types in a where clause. |
| |
| |
| pub trait Foo { |
| type A; |
| fn boo(&self) -> <Self as Foo>::A; |
| } |
| |
| #[derive(PartialEq, Debug)] |
| pub struct Bar; |
| |
| impl Foo for isize { |
| type A = usize; |
| fn boo(&self) -> usize { 42 } |
| } |
| |
| impl Foo for Bar { |
| type A = isize; |
| fn boo(&self) -> isize { 43 } |
| } |
| |
| impl Foo for char { |
| type A = Bar; |
| fn boo(&self) -> Bar { Bar } |
| } |
| |
| fn foo1<I: Foo<A=Bar>>(x: I) -> Bar { |
| x.boo() |
| } |
| |
| fn foo2<I: Foo>(x: I) -> <I as Foo>::A { |
| x.boo() |
| } |
| |
| pub fn main() { |
| let a = 42; |
| assert_eq!(foo2(a), 42); |
| |
| let a = Bar; |
| assert_eq!(foo2(a), 43); |
| |
| let a = 'a'; |
| foo1(a); |
| assert_eq!(foo2(a), Bar); |
| } |