| //@ run-pass |
| struct Foo<A = (isize, char)> { |
| a: A |
| } |
| |
| impl Foo<isize> { |
| fn bar_int(&self) -> isize { |
| self.a |
| } |
| } |
| |
| impl Foo<char> { |
| fn bar_char(&self) -> char { |
| self.a |
| } |
| } |
| |
| impl Foo { |
| fn bar(&self) { |
| let (i, c): (isize, char) = self.a; |
| assert_eq!(Foo { a: i }.bar_int(), i); |
| assert_eq!(Foo { a: c }.bar_char(), c); |
| } |
| } |
| |
| impl<A: Clone> Foo<A> { |
| fn baz(&self) -> A { |
| self.a.clone() |
| } |
| } |
| |
| fn default_foo(x: Foo) { |
| let (i, c): (isize, char) = x.a; |
| assert_eq!(i, 1); |
| assert_eq!(c, 'a'); |
| |
| x.bar(); |
| assert_eq!(x.baz(), (1, 'a')); |
| } |
| |
| #[derive(PartialEq, Debug)] |
| struct BazHelper<T>(T); |
| |
| #[derive(PartialEq, Debug)] |
| // Ensure that we can use previous type parameters in defaults. |
| struct Baz<T, U = BazHelper<T>, V = Option<U>>(T, U, V); |
| |
| fn main() { |
| default_foo(Foo { a: (1, 'a') }); |
| |
| let x: Baz<bool> = Baz(true, BazHelper(false), Some(BazHelper(true))); |
| assert_eq!(x, Baz(true, BazHelper(false), Some(BazHelper(true)))); |
| } |