1 files changed, 28 insertions, 0 deletions
diff --git a/tests/ui/borrowck/borrowck-mut-borrow-of-mut-base-ptr.rs b/tests/ui/borrowck/borrowck-mut-borrow-of-mut-base-ptr.rs
new file mode 100644
index 000000000..6174893ba
--- /dev/null
+++ b/tests/ui/borrowck/borrowck-mut-borrow-of-mut-base-ptr.rs
@@ -0,0 +1,28 @@
+// Test that attempt to mutably borrow `&mut` pointer while pointee is
+// borrowed yields an error.
+//
+// Example from compiler/rustc_borrowck/borrowck/README.md
+
+
+
+fn foo<'a>(mut t0: &'a mut isize,
+           mut t1: &'a mut isize) {
+    let p: &isize = &*t0;     // Freezes `*t0`
+    let mut t2 = &mut t0;   //~ ERROR cannot borrow `t0`
+    **t2 += 1;              // Mutates `*t0`
+    p.use_ref();
+}
+
+fn bar<'a>(mut t0: &'a mut isize,
+           mut t1: &'a mut isize) {
+    let p: &mut isize = &mut *t0; // Claims `*t0`
+    let mut t2 = &mut t0;       //~ ERROR cannot borrow `t0`
+    **t2 += 1;                  // Mutates `*t0` but not through `*p`
+    p.use_mut();
+}
+
+fn main() {
+}
+
+trait Fake { fn use_mut(&mut self) { } fn use_ref(&self) { }  }
+impl<T> Fake for T { }