1 files changed, 65 insertions, 0 deletions
diff --git a/tests/ui/union/field_checks.rs b/tests/ui/union/field_checks.rs
new file mode 100644
index 000000000..d5d1e44ac
--- /dev/null
+++ b/tests/ui/union/field_checks.rs
@@ -0,0 +1,65 @@
+use std::mem::ManuallyDrop;
+
+union U1 { // OK
+    a: u8,
+}
+
+union U2<T: Copy> { // OK
+    a: T,
+}
+
+union U22<T> { // OK
+    a: ManuallyDrop<T>,
+}
+
+union U23<T> { // OK
+    a: (ManuallyDrop<T>, i32),
+}
+
+union U24<T> { // OK
+    a: [ManuallyDrop<T>; 2],
+}
+
+union U3 {
+    a: String, //~ ERROR unions cannot contain fields that may need dropping
+}
+
+union U32 { // field that does not drop but is not `Copy`, either
+    a: std::cell::RefCell<i32>, //~ ERROR unions cannot contain fields that may need dropping
+}
+
+union U4<T> {
+    a: T, //~ ERROR unions cannot contain fields that may need dropping
+}
+
+union U5 { // Having a drop impl is OK
+    a: u8,
+}
+
+impl Drop for U5 {
+    fn drop(&mut self) {}
+}
+
+union U5Nested { // a nested union that drops is NOT OK
+    nest: U5, //~ ERROR unions cannot contain fields that may need dropping
+}
+
+union U5Nested2 { // for now we don't special-case empty arrays
+    nest: [U5; 0], //~ ERROR unions cannot contain fields that may need dropping
+}
+
+union U6 { // OK
+    s: &'static i32,
+    m: &'static mut i32,
+}
+
+union U7<T> { // OK
+    f: (&'static mut i32, ManuallyDrop<T>, i32),
+}
+
+union U8<T> { // OK
+    f1: [(&'static mut i32, i32); 8],
+    f2: [ManuallyDrop<T>; 2],
+}
+
+fn main() {}