move_ref_patterns: introduce tests

bindings_after_at: harden tests

src/test/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.rs

@@ -0,0 +1,50 @@
+#![feature(move_ref_pattern)]
+
+fn main() {}
+
+struct U;
+
+fn slice() {
+    let mut arr = [U, U, U, U, U];
+    let hold_all = &arr;
+    let [ref _x0_hold, _x1, ref xs_hold @ ..] = arr; //~ ERROR cannot move out of `arr[..]`
+    _x1 = U; //~ ERROR cannot assign twice to immutable variable `_x1`
+    drop(hold_all);
+    let [_x0, ..] = arr; //~ ERROR cannot move out of `arr[..]`
+    drop(_x0_hold);
+    let [_, _, ref mut _x2, _x3, mut _x4] = arr;
+    //~^ ERROR cannot borrow `arr[..]` as mutable
+    //~| ERROR cannot move out of `arr[..]` because it is borrowed
+    //~| ERROR cannot move out of `arr[..]` because it is borrowed
+    drop(xs_hold);
+}
+
+fn tuple() {
+    let mut tup = (U, U, U, U);
+    let (ref _x0, _x1, ref _x2, ..) = tup;
+    _x1 = U; //~ ERROR cannot assign twice to immutable variable
+    let _x0_hold = &mut tup.0; //~ ERROR cannot borrow `tup.0` as mutable because it is also
+    let (ref mut _x0_hold, ..) = tup; //~ ERROR cannot borrow `tup.0` as mutable because it is also
+    *_x0 = U; //~ ERROR cannot assign to `*_x0` which is behind a `&` reference
+    *_x2 = U; //~ ERROR cannot assign to `*_x2` which is behind a `&` reference
+    drop(tup.1); //~ ERROR use of moved value: `tup.1`
+    let _x1_hold = &tup.1; //~ ERROR borrow of moved value: `tup.1`
+    let (.., ref mut _x3) = tup;
+    let _x3_hold = &tup.3; //~ ERROR cannot borrow `tup.3` as immutable
+    let _x3_hold = &mut tup.3; //~ ERROR cannot borrow `tup.3` as mutable more
+    let (.., ref mut _x4_hold) = tup; //~ ERROR cannot borrow `tup.3` as mutable more
+    let (.., ref _x4_hold) = tup; //~ ERROR cannot borrow `tup.3` as immutable
+    drop(_x3);
+}
+
+fn closure() {
+    let mut tup = (U, U, U);
+    let c1 = || {
+        let (ref _x0, _x1, _) = tup;
+    };
+    let c2 = || {
+        //~^ ERROR use of moved value
+        let (ref mut _x0, _, _x2) = tup;
+    };
+    drop(c1);
+}