Auto merge of #68376 - Centril:move-ref-patterns, r=matthewjasper

Initial implementation of `#![feature(move_ref_pattern)]`

Following up on #45600, under the gate `#![feature(move_ref_pattern)]`, `(ref x, mut y)` is allowed subject to restrictions necessary for soundness. The match checking implementation and tests for `#![feature(bindings_after_at)]` is also adjusted as necessary.

Closes #45600.
Tracking issue: #68354.

r? @matthewjasper

1 files changed, 23 insertions, 0 deletions

diff --git a/src/test/ui/pattern/move-ref-patterns/feature-gate-move_ref_pattern.rs b/src/test/ui/pattern/move-ref-patterns/feature-gate-move_ref_pattern.rs
new file mode 100644
index 00000000000..fb92eb1ba32
--- /dev/null
+++ b/src/test/ui/pattern/move-ref-patterns/feature-gate-move_ref_pattern.rs
@@ -0,0 +1,23 @@
+fn main() {
+    #[derive(Clone)]
+    struct X {
+        x: (),
+    }
+    let mut tup = (X { x: () }, X { x: () });
+    match Some(tup.clone()) {
+        Some((y, ref z)) => {}
+        //~^ ERROR binding by-move and by-ref in the same pattern is unstable
+        None => panic!(),
+    }
+
+    let (ref a, b) = tup.clone();
+    //~^ ERROR binding by-move and by-ref in the same pattern is unstable
+
+    let (a, mut b) = &tup;
+    //~^ ERROR binding by-move and by-ref in the same pattern is unstable
+    //~| ERROR cannot move out of a shared reference
+
+    let (mut a, b) = &mut tup;
+    //~^ ERROR binding by-move and by-ref in the same pattern is unstable
+    //~| ERROR cannot move out of a mutable reference
+}