1 files changed, 36 insertions, 0 deletions
diff --git a/src/test/ui/dst/dst-bad-coerce1.rs b/src/test/ui/dst/dst-bad-coerce1.rs
new file mode 100644
index 000000000..7ef237e39
--- /dev/null
+++ b/src/test/ui/dst/dst-bad-coerce1.rs
@@ -0,0 +1,36 @@
+// Attempt to change the type as well as unsizing.
+
+#![feature(unsized_tuple_coercion)]
+
+struct Fat<T: ?Sized> {
+    ptr: T
+}
+
+struct Foo;
+trait Bar { fn bar(&self) {} }
+
+pub fn main() {
+    // With a vec of isize.
+    let f1 = Fat { ptr: [1, 2, 3] };
+    let f2: &Fat<[isize; 3]> = &f1;
+    let f3: &Fat<[usize]> = f2;
+    //~^ ERROR mismatched types
+
+    // With a trait.
+    let f1 = Fat { ptr: Foo };
+    let f2: &Fat<Foo> = &f1;
+    let f3: &Fat<dyn Bar> = f2;
+    //~^ ERROR `Foo: Bar` is not satisfied
+
+    // Tuple with a vec of isize.
+    let f1 = ([1, 2, 3],);
+    let f2: &([isize; 3],) = &f1;
+    let f3: &([usize],) = f2;
+    //~^ ERROR mismatched types
+
+    // Tuple with a trait.
+    let f1 = (Foo,);
+    let f2: &(Foo,) = &f1;
+    let f3: &(dyn Bar,) = f2;
+    //~^ ERROR `Foo: Bar` is not satisfied
+}