1 files changed, 26 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/uninit.rs b/src/tools/clippy/tests/ui/uninit.rs
new file mode 100644
index 000000000..dac5ce272
--- /dev/null
+++ b/src/tools/clippy/tests/ui/uninit.rs
@@ -0,0 +1,26 @@
+#![feature(stmt_expr_attributes)]
+#![allow(clippy::let_unit_value)]
+
+use std::mem::{self, MaybeUninit};
+
+fn main() {
+    let _: usize = unsafe { MaybeUninit::uninit().assume_init() };
+
+    // edge case: For now we lint on empty arrays
+    let _: [u8; 0] = unsafe { MaybeUninit::uninit().assume_init() };
+
+    // edge case: For now we accept unit tuples
+    let _: () = unsafe { MaybeUninit::uninit().assume_init() };
+
+    // This is OK, because `MaybeUninit` allows uninitialized data.
+    let _: MaybeUninit<usize> = unsafe { MaybeUninit::uninit().assume_init() };
+
+    // This is OK, because all constitutent types are uninit-compatible.
+    let _: (MaybeUninit<usize>, MaybeUninit<bool>) = unsafe { MaybeUninit::uninit().assume_init() };
+
+    // This is OK, because all constitutent types are uninit-compatible.
+    let _: (MaybeUninit<usize>, [MaybeUninit<bool>; 2]) = unsafe { MaybeUninit::uninit().assume_init() };
+
+    // Was a false negative.
+    let _: usize = unsafe { mem::MaybeUninit::uninit().assume_init() };
+}