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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:19:13 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:19:13 +0000
commit218caa410aa38c29984be31a5229b9fa717560ee (patch)
treec54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/transmutability/unions/should_reject_intersecting.rs
parentReleasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff)
downloadrustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz
rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/transmutability/unions/should_reject_intersecting.rs')
-rw-r--r--tests/ui/transmutability/unions/should_reject_intersecting.rs38
1 files changed, 38 insertions, 0 deletions
diff --git a/tests/ui/transmutability/unions/should_reject_intersecting.rs b/tests/ui/transmutability/unions/should_reject_intersecting.rs
new file mode 100644
index 000000000..9cd4233ee
--- /dev/null
+++ b/tests/ui/transmutability/unions/should_reject_intersecting.rs
@@ -0,0 +1,38 @@
+//! ALL valid bit patterns of the source must be valid bit patterns of the
+//! destination type, unless validity is assumed.
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code, incomplete_features, non_camel_case_types)]
+
+mod assert {
+ use std::mem::{Assume, BikeshedIntrinsicFrom};
+ pub struct Context;
+
+ pub fn is_transmutable<Src, Dst>()
+ where
+ Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY }>
+ // validity is NOT assumed --------------^^^^^^^^^^^^^^^^^^
+ {}
+}
+
+#[derive(Clone, Copy)] #[repr(u8)] enum Ox00 { V = 0x00 }
+#[derive(Clone, Copy)] #[repr(u8)] enum Ox7F { V = 0x7F }
+#[derive(Clone, Copy)] #[repr(u8)] enum OxFF { V = 0xFF }
+
+fn test() {
+ #[repr(C)]
+ union A {
+ a: Ox00,
+ b: Ox7F,
+ }
+
+ #[repr(C)]
+ union B {
+ a: Ox7F,
+ b: OxFF,
+ }
+
+ assert::is_transmutable::<A, B>(); //~ ERROR cannot be safely transmuted
+ assert::is_transmutable::<B, A>(); //~ ERROR cannot be safely transmuted
+}