1 files changed, 23 insertions, 0 deletions
diff --git a/tests/ui/ptr-coercion.rs b/tests/ui/ptr-coercion.rs
new file mode 100644
index 000000000..193899034
--- /dev/null
+++ b/tests/ui/ptr-coercion.rs
@@ -0,0 +1,23 @@
+// Test coercions between pointers which don't do anything fancy like unsizing.
+// These are testing that we don't lose mutability when converting to raw pointers.
+
+pub fn main() {
+    // *const -> *mut
+    let x: *const isize = &42;
+    let x: *mut isize = x; //~  ERROR mismatched types
+                           //~| expected raw pointer `*mut isize`
+                           //~| found raw pointer `*const isize`
+                           //~| types differ in mutability
+
+    // & -> *mut
+    let x: *mut isize = &42; //~  ERROR mismatched types
+                             //~| expected raw pointer `*mut isize`
+                             //~| found reference `&isize`
+                             //~| types differ in mutability
+
+    let x: *const isize = &42;
+    let x: *mut isize = x; //~  ERROR mismatched types
+                           //~| expected raw pointer `*mut isize`
+                           //~| found raw pointer `*const isize`
+                           //~| types differ in mutability
+}