1 files changed, 54 insertions, 0 deletions
diff --git a/tests/ui/lint/unused/must_use-array.rs b/tests/ui/lint/unused/must_use-array.rs
new file mode 100644
index 00000000000..b7bae4b0acf
--- /dev/null
+++ b/tests/ui/lint/unused/must_use-array.rs
@@ -0,0 +1,54 @@
+#![deny(unused_must_use)]
+
+#[must_use]
+#[derive(Clone, Copy)]
+struct S;
+
+struct A;
+
+#[must_use]
+trait T {}
+
+impl T for A {}
+
+fn empty() -> [S; 0] {
+    []
+}
+
+fn singleton() -> [S; 1] {
+    [S]
+}
+
+fn many() -> [S; 4] {
+    [S, S, S, S]
+}
+
+fn array_of_impl_trait() -> [impl T; 2] {
+    [A, A]
+}
+
+fn impl_array() -> [(u8, Box<dyn T>); 2] {
+    [(0, Box::new(A)), (0, Box::new(A))]
+}
+
+fn array_of_arrays_of_arrays() -> [[[S; 1]; 2]; 1] {
+    [[[S], [S]]]
+}
+
+fn usize_max() -> [S; usize::MAX] {
+    [S; usize::MAX]
+}
+
+fn main() {
+    empty(); // ok
+    singleton(); //~ ERROR unused array of `S` that must be used
+    many(); //~ ERROR unused array of `S` that must be used
+    ([S], 0, ()); //~ ERROR unused array of `S` in tuple element 0 that must be used
+    array_of_impl_trait(); //~ ERROR unused array of implementers of `T` that must be used
+    impl_array();
+    //~^ ERROR unused array of boxed `T` trait objects in tuple element 1 that must be used
+    array_of_arrays_of_arrays();
+    //~^ ERROR unused array of arrays of arrays of `S` that must be used
+    usize_max();
+    //~^ ERROR unused array of `S` that must be used
+}