1 files changed, 37 insertions, 0 deletions
diff --git a/src/test/ui/consts/miri_unleashed/mutable_references.rs b/src/test/ui/consts/miri_unleashed/mutable_references.rs
new file mode 100644
index 000000000..ca927ef4a
--- /dev/null
+++ b/src/test/ui/consts/miri_unleashed/mutable_references.rs
@@ -0,0 +1,37 @@
+// compile-flags: -Zunleash-the-miri-inside-of-you
+#![allow(const_err)]
+
+use std::cell::UnsafeCell;
+
+// a test demonstrating what things we could allow with a smarter const qualification
+
+// this is fine because is not possible to mutate through an immutable reference.
+static FOO: &&mut u32 = &&mut 42;
+
+// this is fine because accessing an immutable static `BAR` is equivalent to accessing `*&BAR`
+// which puts the mutable reference behind an immutable one.
+static BAR: &mut () = &mut ();
+
+struct Foo<T>(T);
+
+// this is fine for the same reason as `BAR`.
+static BOO: &mut Foo<()> = &mut Foo(());
+
+// interior mutability is fine
+struct Meh {
+    x: &'static UnsafeCell<i32>,
+}
+unsafe impl Sync for Meh {}
+static MEH: Meh = Meh {
+    x: &UnsafeCell::new(42),
+};
+
+// this is fine for the same reason as `BAR`.
+static OH_YES: &mut i32 = &mut 42;
+
+fn main() {
+    unsafe {
+        *MEH.x.get() = 99;
+    }
+    *OH_YES = 99; //~ ERROR cannot assign to `*OH_YES`, as `OH_YES` is an immutable static item
+}