1 files changed, 45 insertions, 0 deletions
diff --git a/src/test/ui/union/union-const-eval-field.rs b/src/test/ui/union/union-const-eval-field.rs
new file mode 100644
index 000000000..ca48785cd
--- /dev/null
+++ b/src/test/ui/union/union-const-eval-field.rs
@@ -0,0 +1,45 @@
+// run-pass
+// revisions: mirunsafeck thirunsafeck
+// [thirunsafeck]compile-flags: -Z thir-unsafeck
+
+type Field1 = (i32, u32);
+type Field2 = f32;
+type Field3 = i64;
+
+union DummyUnion {
+    field1: Field1,
+    field2: Field2,
+    field3: Field3,
+}
+
+const FLOAT1_AS_I32: i32 = 1065353216;
+const UNION: DummyUnion = DummyUnion { field1: (FLOAT1_AS_I32, 0) };
+
+const fn read_field1() -> Field1 {
+    const FIELD1: Field1 = unsafe { UNION.field1 };
+    FIELD1
+}
+
+const fn read_field2() -> Field2 {
+    const FIELD2: Field2 = unsafe { UNION.field2 };
+    FIELD2
+}
+
+const fn read_field3() -> Field3 {
+    const FIELD3: Field3 = unsafe { UNION.field3 };
+    FIELD3
+}
+
+fn main() {
+    let foo = FLOAT1_AS_I32;
+    assert_eq!(read_field1().0, foo);
+    assert_eq!(read_field1().0, FLOAT1_AS_I32);
+
+    let foo = 1.0;
+    assert_eq!(read_field2(), foo);
+    assert_eq!(read_field2(), 1.0);
+
+    assert_eq!(read_field3(), unsafe { UNION.field3 });
+    let foo = unsafe { UNION.field3 };
+    assert_eq!(read_field3(), foo);
+}