extract expected return type from `-> impl Future` obligation

2 files changed, 59 insertions, 0 deletions

diff --git a/src/test/ui/async-await/return-ty-raw-ptr-coercion.rs b/src/test/ui/async-await/return-ty-raw-ptr-coercion.rs
new file mode 100644
index 00000000000..570e745f8c7
--- /dev/null
+++ b/src/test/ui/async-await/return-ty-raw-ptr-coercion.rs
@@ -0,0 +1,25 @@
+// Check that we apply unsizing coercions based on the return type.
+//
+// Also serves as a regression test for #60424.
+//
+// edition:2018
+// check-pass
+
+#![allow(warnings)]
+
+use std::fmt::Debug;
+
+const TMP: u32 = 22;
+
+// Coerce from `Box<"asdf">` to `Box<dyn Debug>`.
+fn raw_pointer_coercion() {
+    fn sync_example() -> *const u32 {
+        &TMP
+    }
+
+    async fn async_example() -> *const u32 {
+        &TMP
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/return-ty-unsize-coercion.rs b/src/test/ui/async-await/return-ty-unsize-coercion.rs
new file mode 100644
index 00000000000..4d1b87677ed
--- /dev/null
+++ b/src/test/ui/async-await/return-ty-unsize-coercion.rs
@@ -0,0 +1,34 @@
+// Check that we apply unsizing coercions based on the return type.
+//
+// Also serves as a regression test for #60424.
+//
+// edition:2018
+// check-pass
+
+#![allow(warnings)]
+
+use std::fmt::Debug;
+
+// Coerce from `Box<"asdf">` to `Box<dyn Debug>`.
+fn unsize_trait_coercion() {
+    fn sync_example() -> Box<dyn Debug> {
+        Box::new("asdf")
+    }
+
+    async fn async_example() -> Box<dyn Debug> {
+        Box::new("asdf")
+    }
+}
+
+// Coerce from `Box<[u32; N]>` to `Box<[32]>`.
+fn unsize_slice_coercion() {
+    fn sync_example() -> Box<[u32]> {
+        Box::new([0])
+    }
+
+    async fn async_example() -> Box<[u32]> {
+        Box::new([0])
+    }
+}
+
+fn main() {}