Rollup merge of #60799 - matthewjasper:allow-bound-regions-in-existential-types, r=oli-obk

Allow late-bound regions in existential types

closes #60655
r? @oli-obk

1 files changed, 30 insertions, 0 deletions

diff --git a/src/test/ui/existential_types/issue-60655-latebound-regions.rs b/src/test/ui/existential_types/issue-60655-latebound-regions.rs
new file mode 100644
index 00000000000..a4fe8650129
--- /dev/null
+++ b/src/test/ui/existential_types/issue-60655-latebound-regions.rs
@@ -0,0 +1,30 @@
+// Test that existential types are allowed to contain late-bound regions.
+
+// compile-pass
+// edition:2018
+
+#![feature(async_await, existential_type)]
+
+use std::future::Future;
+
+pub existential type Func: Sized;
+
+// Late bound region should be allowed to escape the function, since it's bound
+// in the type.
+fn null_function_ptr() -> Func {
+    None::<for<'a> fn(&'a ())>
+}
+
+async fn async_nop(_: &u8) {}
+
+pub existential type ServeFut: Future<Output=()>;
+
+// Late bound regions occur in the generator witness type here.
+fn serve() -> ServeFut {
+    async move {
+        let x = 5;
+        async_nop(&x).await
+    }
+}
+
+fn main() {}