1 files changed, 57 insertions, 0 deletions
diff --git a/src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs b/src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs
new file mode 100644
index 000000000..55c6aa795
--- /dev/null
+++ b/src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs
@@ -0,0 +1,57 @@
+#![allow(warnings)]
+
+fn closure_expecting_bound<F>(_: F)
+where
+    F: FnOnce(&u32),
+{
+}
+
+fn closure_expecting_free<'a, F>(_: F)
+where
+    F: FnOnce(&'a u32),
+{
+}
+
+fn expect_bound_supply_nothing() {
+    // Because `x` is inferred to have a bound region, we cannot allow
+    // it to escape into `f`:
+    let mut f: Option<&u32> = None;
+    closure_expecting_bound(|x| {
+        f = Some(x); //~ ERROR borrowed data escapes outside of closure
+    });
+}
+
+fn expect_bound_supply_bound() {
+    // Because `x` is inferred to have a bound region, we cannot allow
+    // it to escape into `f`, even with an explicit type annotation on
+    // closure:
+    let mut f: Option<&u32> = None;
+    closure_expecting_bound(|x: &u32| {
+        f = Some(x); //~ ERROR borrowed data escapes outside of closure
+    });
+}
+
+fn expect_free_supply_nothing() {
+    let mut f: Option<&u32> = None;
+    closure_expecting_free(|x| f = Some(x)); // OK
+}
+
+fn expect_free_supply_bound() {
+    let mut f: Option<&u32> = None;
+
+    // Here, even though the annotation `&u32` could be seen as being
+    // bound in the closure, we permit it to be defined as a free
+    // region (which is inferred to something in the fn body).
+    closure_expecting_free(|x: &u32| f = Some(x)); // OK
+}
+
+fn expect_free_supply_named<'x>() {
+    let mut f: Option<&u32> = None;
+
+    // Here, even though the annotation `&u32` could be seen as being
+    // bound in the closure, we permit it to be defined as a free
+    // region (which is inferred to something in the fn body).
+    closure_expecting_free(|x: &'x u32| f = Some(x)); // OK
+}
+
+fn main() {}