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//@ run-pass
#![allow(dead_code)]
// Test that pointers and references to extern types are thin, ie they have the same size and
// alignment as a pointer to ().
#![feature(extern_types)]
use std::mem::{align_of, size_of};
extern "C" {
type A;
}
struct Foo {
x: u8,
tail: A,
}
struct Bar<T: ?Sized> {
x: u8,
tail: T,
}
fn assert_thin<T: ?Sized>() {
assert_eq!(size_of::<*const T>(), size_of::<*const ()>());
assert_eq!(align_of::<*const T>(), align_of::<*const ()>());
assert_eq!(size_of::<*mut T>(), size_of::<*mut ()>());
assert_eq!(align_of::<*mut T>(), align_of::<*mut ()>());
assert_eq!(size_of::<&T>(), size_of::<&()>());
assert_eq!(align_of::<&T>(), align_of::<&()>());
assert_eq!(size_of::<&mut T>(), size_of::<&mut ()>());
assert_eq!(align_of::<&mut T>(), align_of::<&mut ()>());
}
fn main() {
assert_thin::<A>();
assert_thin::<Foo>();
assert_thin::<Bar<A>>();
assert_thin::<Bar<Bar<A>>>();
}
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