// run-pass #![allow(dead_code)] struct Foo<T: ?Sized> { a: u16, b: T } trait Bar { fn get(&self) -> usize; } impl Bar for usize { fn get(&self) -> usize { *self } } struct Baz<T: ?Sized> { a: T } struct HasDrop<T: ?Sized> { ptr: Box<usize>, data: T } fn main() { // Test that zero-offset works properly let b : Baz<usize> = Baz { a: 7 }; assert_eq!(b.a.get(), 7); let b : &Baz<dyn Bar> = &b; assert_eq!(b.a.get(), 7); // Test that the field is aligned properly let f : Foo<usize> = Foo { a: 0, b: 11 }; assert_eq!(f.b.get(), 11); let ptr1 : *const u8 = &f.b as *const _ as *const u8; let f : &Foo<dyn Bar> = &f; let ptr2 : *const u8 = &f.b as *const _ as *const u8; assert_eq!(f.b.get(), 11); // The pointers should be the same assert_eq!(ptr1, ptr2); // Test that nested DSTs work properly let f : Foo<Foo<usize>> = Foo { a: 0, b: Foo { a: 1, b: 17 }}; assert_eq!(f.b.b.get(), 17); let f : &Foo<Foo<dyn Bar>> = &f; assert_eq!(f.b.b.get(), 17); // Test that get the pointer via destructuring works let f : Foo<usize> = Foo { a: 0, b: 11 }; let f : &Foo<dyn Bar> = &f; let &Foo { a: _, b: ref bar } = f; assert_eq!(bar.get(), 11); // Make sure that drop flags don't screw things up let d : HasDrop<Baz<[i32; 4]>> = HasDrop { ptr: Box::new(0), data: Baz { a: [1,2,3,4] } }; assert_eq!([1,2,3,4], d.data.a); let d : &HasDrop<Baz<[i32]>> = &d; assert_eq!(&[1,2,3,4], &d.data.a); }