add move-expression tests for generator closures

Author: TaKO8Ki

tests/ui/move-expr/gen-closures.rs

@@ -0,0 +1,46 @@
+//@ run-pass
+
+#![allow(incomplete_features)]
+#![feature(iter_macro, move_expr, yield_expr)]
+
+use std::cell::Cell;
+use std::iter::iter;
+use std::sync::Arc;
+
+fn main() {
+    let created = Cell::new(0);
+    let closure = iter! { || {
+        let n = move({
+            created.set(created.get() + 1);
+            created.get()
+        });
+        yield n;
+    }};
+    assert_eq!(created.get(), 1);
+    assert_eq!(closure().next(), Some(1));
+    assert_eq!(closure().next(), Some(1));
+    assert_eq!(created.get(), 1);
+
+    let x = Arc::new(String::from("hello"));
+    assert_eq!(Arc::strong_count(&x), 1);
+
+    let closure = iter! { || {
+        yield move(x.clone());
+    }};
+    assert_eq!(Arc::strong_count(&x), 2);
+    let mut generator = closure();
+    assert_eq!(Arc::strong_count(&x), 2);
+    let yielded = generator.next().unwrap();
+    assert_eq!(Arc::strong_count(&x), 2);
+    assert_eq!(generator.next(), None);
+    drop(yielded);
+    assert_eq!(Arc::strong_count(&x), 1);
+
+    let a = String::from("a");
+    let b = String::from("bbb");
+    let closure = iter! { || {
+        let moved = move(a.clone());
+        yield (moved, b.len());
+    }};
+    assert_eq!(closure().next(), Some((String::from("a"), 3)));
+}