add tests

src/test/ui/pattern/bindings-after-at/bind-by-copy.rs

@@ -0,0 +1,49 @@
+// run-pass
+
+// Test copy
+
+#![feature(bindings_after_at)]
+
+struct A { a: i32, b: i32 }
+struct B { a: i32, b: C }
+struct D { a: i32, d: C }
+#[derive(Copy,Clone)]
+struct C { c: i32 }
+
+pub fn main() {
+    match (A {a: 10, b: 20}) {
+        x@A {a, b: 20} => { assert!(x.a == 10); assert!(a == 10); }
+        A {b: _b, ..} => { panic!(); }
+    }
+
+    let mut x@B {b, ..} = B {a: 10, b: C {c: 20}};
+    assert_eq!(x.a, 10);
+    x.b.c = 30;
+    assert_eq!(b.c, 20);
+    let mut y@D {d, ..} = D {a: 10, d: C {c: 20}};
+    assert_eq!(y.a, 10);
+    y.d.c = 30;
+    assert_eq!(d.c, 20);
+
+    let some_b = Some(B { a: 10, b: C { c: 20 } });
+
+    // in irrefutable pattern
+    if let Some(x @ B { b, .. }) = some_b {
+        assert_eq!(x.b.c, 20);
+        assert_eq!(b.c, 20);
+    } else {
+        unreachable!();
+    }
+
+    let some_b = Some(B { a: 10, b: C { c: 20 } });
+
+    if let Some(x @ B { b: mut b @ C { c }, .. }) = some_b {
+        assert_eq!(x.b.c, 20);
+        assert_eq!(b.c, 20);
+        b.c = 30;
+        assert_eq!(b.c, 30);
+        assert_eq!(c, 20);
+    } else {
+        unreachable!();
+    }
+}