1 files changed, 74 insertions, 0 deletions
diff --git a/tests/ui/overloaded/overloaded-autoderef-count.rs b/tests/ui/overloaded/overloaded-autoderef-count.rs
new file mode 100644
index 000000000..d58deda09
--- /dev/null
+++ b/tests/ui/overloaded/overloaded-autoderef-count.rs
@@ -0,0 +1,74 @@
+// run-pass
+use std::cell::Cell;
+use std::ops::{Deref, DerefMut};
+
+#[derive(PartialEq)]
+struct DerefCounter<T> {
+    count_imm: Cell<usize>,
+    count_mut: usize,
+    value: T
+}
+
+impl<T> DerefCounter<T> {
+    fn new(value: T) -> DerefCounter<T> {
+        DerefCounter {
+            count_imm: Cell::new(0),
+            count_mut: 0,
+            value: value
+        }
+    }
+
+    fn counts(&self) -> (usize, usize) {
+        (self.count_imm.get(), self.count_mut)
+    }
+}
+
+impl<T> Deref for DerefCounter<T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        self.count_imm.set(self.count_imm.get() + 1);
+        &self.value
+    }
+}
+
+impl<T> DerefMut for DerefCounter<T> {
+    fn deref_mut(&mut self) -> &mut T {
+        self.count_mut += 1;
+        &mut self.value
+    }
+}
+
+#[derive(PartialEq, Debug)]
+struct Point {
+    x: isize,
+    y: isize
+}
+
+impl Point {
+    fn get(&self) -> (isize, isize) {
+        (self.x, self.y)
+    }
+}
+
+pub fn main() {
+    let mut p = DerefCounter::new(Point {x: 0, y: 0});
+
+    let _ = p.x;
+    assert_eq!(p.counts(), (1, 0));
+
+    let _ = &p.x;
+    assert_eq!(p.counts(), (2, 0));
+
+    let _ = &mut p.y;
+    assert_eq!(p.counts(), (2, 1));
+
+    p.x += 3;
+    assert_eq!(p.counts(), (2, 2));
+
+    p.get();
+    assert_eq!(p.counts(), (3, 2));
+
+    // Check the final state.
+    assert_eq!(*p, Point {x: 3, y: 0});
+}