1 files changed, 0 insertions, 54 deletions
diff --git a/src/test/ui/union/union-nonzero.rs b/src/test/ui/union/union-nonzero.rs
deleted file mode 100644
index 3f4f7ea1c..000000000
--- a/src/test/ui/union/union-nonzero.rs
+++ /dev/null
@@ -1,54 +0,0 @@
-// run-pass
-// revisions: mirunsafeck thirunsafeck
-// [thirunsafeck]compile-flags: -Z thir-unsafeck
-
-#![allow(dead_code)]
-
-// Tests that unions aren't subject to unsafe non-zero/niche-filling optimizations.
-//
-// For example, if a union `U` can contain both a `&T` and a `*const T`, there's definitely no
-// bit-value that an `Option<U>` could reuse as `None`; this test makes sure that isn't done.
-//
-// Secondly, this tests the status quo (not a guarantee; subject to change!) to not apply such
-// optimizations to types containing unions even if they're theoretically possible. (discussion:
-// https://github.com/rust-lang/rust/issues/36394)
-//
-// Notably this nails down part of the behavior that `MaybeUninit` assumes: that an
-// `Option<MaybeUninit<&u8>>` does not take advantage of non-zero optimization, and thus is a safe
-// construct.
-
-use std::mem::{size_of, transmute};
-
-union U1<A: Copy> {
-    a: A,
-}
-
-union U2<A: Copy, B: Copy> {
-    a: A,
-    b: B,
-}
-
-// Option<E> uses a value other than 0 and 1 as None
-#[derive(Clone,Copy)]
-enum E {
-    A = 0,
-    B = 1,
-}
-
-fn main() {
-    // Unions do not participate in niche-filling/non-zero optimization...
-    assert!(size_of::<Option<U2<&u8, u8>>>() > size_of::<U2<&u8, u8>>());
-    assert!(size_of::<Option<U2<&u8, ()>>>() > size_of::<U2<&u8, ()>>());
-    assert!(size_of::<Option<U2<u8, E>>>() > size_of::<U2<u8, E>>());
-
-    // ...even when theoretically possible:
-    assert!(size_of::<Option<U1<&u8>>>() > size_of::<U1<&u8>>());
-    assert!(size_of::<Option<U2<&u8, &u8>>>() > size_of::<U2<&u8, &u8>>());
-
-    // The unused bits of the () variant can have any value.
-    let zeroed: U2<&u8, ()> = unsafe { transmute(std::ptr::null::<u8>()) };
-
-    if let None = Some(zeroed) {
-        panic!()
-    }
-}