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//@ run-pass
#[repr(align(4))]
struct Foo;
static FOO: Foo = Foo;
fn main() {
// There's no stable guarantee that these are true.
// However, we want them to be true so that our LLVM IR and runtime are a bit faster:
// a constant address is cheap and doesn't result in relocations in comparison to a "real"
// global somewhere in the data section.
let x: &'static () = &();
assert_eq!(x as *const () as usize, 1);
let x: &'static Foo = &Foo;
assert_eq!(x as *const Foo as usize, 4);
// The exact addresses returned by these library functions are not necessarily stable guarantees
// but for now we assert that we're still matching.
#[allow(dangling_pointers_from_temporaries)]
{
assert_eq!(<Vec<i32>>::new().as_ptr(), <&[i32]>::default().as_ptr());
assert_eq!(<Box<[i32]>>::default().as_ptr(), (&[]).as_ptr());
};
// statics must have a unique address (see https://github.com/rust-lang/rust/issues/18297, not
// clear whether this is a stable guarantee)
assert_ne!(&FOO as *const Foo as usize, 4);
}
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