fix: make expectation returning method unsafe

1 files changed, 7 insertions, 1 deletions

diff --git a/macros/src/expectation.rs b/macros/src/expectation.rs
index 2e86db0..d724655 100644
--- a/macros/src/expectation.rs
+++ b/macros/src/expectation.rs
@@ -439,8 +439,14 @@ impl ToTokens for Expectation
                     }
                 }
 
+                /// Sets the function that will be called to provide the return value of
+                /// this expectation.
+                ///
+                /// # Safety
+                /// The caller must ensure that no argument or return type is outlived. They must
+                /// be treated as if they are bound to 'static.
                 #[allow(unused)]
-                pub fn returning(
+                pub unsafe fn returning(
                     &mut self,
                     func: #returning_fn
                 ) -> &mut Self