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-rw-r--r--src/test/ui/moves/moves-based-on-type-no-recursive-stack-closure.rs35
1 files changed, 35 insertions, 0 deletions
diff --git a/src/test/ui/moves/moves-based-on-type-no-recursive-stack-closure.rs b/src/test/ui/moves/moves-based-on-type-no-recursive-stack-closure.rs
new file mode 100644
index 000000000..86fd37e78
--- /dev/null
+++ b/src/test/ui/moves/moves-based-on-type-no-recursive-stack-closure.rs
@@ -0,0 +1,35 @@
+// Tests correct kind-checking of the reason stack closures without the :Copy
+// bound must be noncopyable. For details see
+// https://smallcultfollowing.com/babysteps/blog/2013/04/30/the-case-of-the-recurring-closure/
+
+struct R<'a> {
+ // This struct is needed to create the
+ // otherwise infinite type of a fn that
+ // accepts itself as argument:
+ c: Box<dyn FnMut(&mut R, bool) + 'a>
+}
+
+fn innocent_looking_victim() {
+ let mut x = Some("hello".to_string());
+ conspirator(|f, writer| {
+ if writer {
+ x = None;
+ } else {
+ match x {
+ Some(ref msg) => {
+ (f.c)(f, true);
+ //~^ ERROR: cannot borrow `*f` as mutable more than once at a time
+ println!("{}", msg);
+ },
+ None => panic!("oops"),
+ }
+ }
+ })
+}
+
+fn conspirator<F>(mut f: F) where F: FnMut(&mut R, bool) {
+ let mut r = R {c: Box::new(f)};
+ f(&mut r, false) //~ ERROR borrow of moved value
+}
+
+fn main() { innocent_looking_victim() }