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// 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);
}
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