PyAny::downcast(): relax lifetime bounds

newsfragments/2734.changed.md

@@ -1,2 +1,3 @@
 `PyAny::cast_as()` and `Py::cast_as()` are now deprecated in favor of
-`PyAny::downcast()` and the new `Py::downcast()`.
+`PyAny::downcast()` and the new `Py::downcast()`. The `PyAny::downcast()`
+lifetime bounds where slightly relaxed.

src/instance.rs

@@ -997,7 +997,7 @@ impl PyObject {
     /// flexible alternative, see [`Py::extract`](struct.Py.html#method.extract).
     pub fn downcast<'p, T>(&'p self, py: Python<'p>) -> Result<&T, PyDowncastError<'_>>
     where
-        for<'py> T: PyTryFrom<'py>,
+        T: PyTryFrom<'p>,
     {
         <T as PyTryFrom<'_>>::try_from(self.as_ref(py))
     }
@@ -1008,7 +1008,7 @@ impl PyObject {
     where
         D: PyTryFrom<'p>,
     {
-        <D as PyTryFrom<'_>>::try_from(self.as_ref(py))
+        self.downcast(py)
     }
 }
 

src/types/any.rs

@@ -752,7 +752,7 @@ impl PyAny {
     where
         D: PyTryFrom<'a>,
     {
-        <D as PyTryFrom<'_>>::try_from(self)
+        self.downcast()
     }
 
     /// Converts this `PyAny` to a concrete Python type.
@@ -773,9 +773,9 @@ impl PyAny {
     ///     assert!(any.downcast::<PyList>().is_err());
     /// });
     /// ```
-    pub fn downcast<T>(&self) -> Result<&T, PyDowncastError<'_>>
+    pub fn downcast<'p, T>(&'p self) -> Result<&'p T, PyDowncastError<'_>>
     where
-        for<'py> T: PyTryFrom<'py>,
+        T: PyTryFrom<'p>,
     {
         <T as PyTryFrom>::try_from(self)
     }