| // run-pass |
| #![feature(box_syntax)] |
| |
| struct Fat<T: ?Sized> { |
| f1: isize, |
| f2: &'static str, |
| ptr: T |
| } |
| |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| struct Bar; |
| |
| #[derive(Copy, Clone, PartialEq, Eq)] |
| struct Bar1 { |
| f: isize |
| } |
| |
| trait ToBar { |
| fn to_bar(&self) -> Bar; |
| fn to_val(&self) -> isize; |
| } |
| |
| impl ToBar for Bar { |
| fn to_bar(&self) -> Bar { |
| *self |
| } |
| fn to_val(&self) -> isize { |
| 0 |
| } |
| } |
| impl ToBar for Bar1 { |
| fn to_bar(&self) -> Bar { |
| Bar |
| } |
| fn to_val(&self) -> isize { |
| self.f |
| } |
| } |
| |
| // x is a fat pointer |
| fn foo(x: &Fat<dyn ToBar>) { |
| assert_eq!(x.f1, 5); |
| assert_eq!(x.f2, "some str"); |
| assert_eq!(x.ptr.to_bar(), Bar); |
| assert_eq!(x.ptr.to_val(), 42); |
| |
| let y = &x.ptr; |
| assert_eq!(y.to_bar(), Bar); |
| assert_eq!(y.to_val(), 42); |
| } |
| |
| fn bar(x: &dyn ToBar) { |
| assert_eq!(x.to_bar(), Bar); |
| assert_eq!(x.to_val(), 42); |
| } |
| |
| fn baz(x: &Fat<Fat<dyn ToBar>>) { |
| assert_eq!(x.f1, 5); |
| assert_eq!(x.f2, "some str"); |
| assert_eq!(x.ptr.f1, 8); |
| assert_eq!(x.ptr.f2, "deep str"); |
| assert_eq!(x.ptr.ptr.to_bar(), Bar); |
| assert_eq!(x.ptr.ptr.to_val(), 42); |
| |
| let y = &x.ptr.ptr; |
| assert_eq!(y.to_bar(), Bar); |
| assert_eq!(y.to_val(), 42); |
| |
| } |
| |
| pub fn main() { |
| let f1 = Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} }; |
| foo(&f1); |
| let f2 = &f1; |
| foo(f2); |
| let f3: &Fat<dyn ToBar> = f2; |
| foo(f3); |
| let f4: &Fat<dyn ToBar> = &f1; |
| foo(f4); |
| let f5: &Fat<dyn ToBar> = &Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} }; |
| foo(f5); |
| |
| // Zero size object. |
| let f6: &Fat<dyn ToBar> = &Fat { f1: 5, f2: "some str", ptr: Bar }; |
| assert_eq!(f6.ptr.to_bar(), Bar); |
| |
| // &* |
| // |
| let f7: Box<dyn ToBar> = Box::new(Bar1 {f :42}); |
| bar(&*f7); |
| |
| // Deep nesting |
| let f1 = |
| Fat { f1: 5, f2: "some str", ptr: Fat { f1: 8, f2: "deep str", ptr: Bar1 {f :42}} }; |
| baz(&f1); |
| let f2 = &f1; |
| baz(f2); |
| let f3: &Fat<Fat<dyn ToBar>> = f2; |
| baz(f3); |
| let f4: &Fat<Fat<dyn ToBar>> = &f1; |
| baz(f4); |
| let f5: &Fat<Fat<dyn ToBar>> = |
| &Fat { f1: 5, f2: "some str", ptr: Fat { f1: 8, f2: "deep str", ptr: Bar1 {f :42}} }; |
| baz(f5); |
| } |