1 files changed, 33 insertions, 0 deletions
diff --git a/src/test/ui/transmute/transmute-fat-pointers.rs b/src/test/ui/transmute/transmute-fat-pointers.rs
new file mode 100644
index 000000000..7c1beffd1
--- /dev/null
+++ b/src/test/ui/transmute/transmute-fat-pointers.rs
@@ -0,0 +1,33 @@
+// normalize-stderr-test "\d+ bits" -> "N bits"
+
+// Tests that are conservative around thin/fat pointer mismatches.
+
+#![allow(dead_code)]
+
+use std::mem::transmute;
+
+fn a<T, U: ?Sized>(x: &[T]) -> &U {
+    unsafe { transmute(x) } //~ ERROR cannot transmute between types of different sizes
+}
+
+fn b<T: ?Sized, U: ?Sized>(x: &T) -> &U {
+    unsafe { transmute(x) } //~ ERROR cannot transmute between types of different sizes
+}
+
+fn c<T, U>(x: &T) -> &U {
+    unsafe { transmute(x) }
+}
+
+fn d<T, U>(x: &[T]) -> &[U] {
+    unsafe { transmute(x) }
+}
+
+fn e<T: ?Sized, U>(x: &T) -> &U {
+    unsafe { transmute(x) } //~ ERROR cannot transmute between types of different sizes
+}
+
+fn f<T, U: ?Sized>(x: &T) -> &U {
+    unsafe { transmute(x) } //~ ERROR cannot transmute between types of different sizes
+}
+
+fn main() { }