add missing IntoPyObject impls

src/conversions/std/osstr.rs

@@ -64,6 +64,17 @@ impl<'py> IntoPyObject<'py> for &OsStr {
     }
 }
 
+impl<'py> IntoPyObject<'py> for &&OsStr {
+    type Target = PyString;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    #[inline]
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        (*self).into_pyobject(py)
+    }
+}
+
 // There's no FromPyObject implementation for &OsStr because albeit possible on Unix, this would
 // be impossible to implement on Windows. Hence it's omitted entirely
 
@@ -208,8 +219,10 @@ impl<'py> IntoPyObject<'py> for &OsString {
 
 #[cfg(test)]
 mod tests {
+    use crate::prelude::IntoPyObject;
     use crate::types::{PyAnyMethods, PyStringMethods};
-    use crate::{types::PyString, IntoPy, PyObject, Python, ToPyObject};
+    use crate::BoundObject;
+    use crate::{types::PyString, IntoPy, PyObject, Python};
     use std::fmt::Debug;
     use std::{
         borrow::Cow,
@@ -239,9 +252,13 @@ mod tests {
     #[test]
     fn test_topyobject_roundtrip() {
         Python::with_gil(|py| {
-            fn test_roundtrip<T: ToPyObject + AsRef<OsStr> + Debug>(py: Python<'_>, obj: T) {
-                let pyobject = obj.to_object(py);
-                let pystring = pyobject.downcast_bound::<PyString>(py).unwrap();
+            fn test_roundtrip<'py, T>(py: Python<'py>, obj: T)
+            where
+                T: IntoPyObject<'py> + AsRef<OsStr> + Debug + Clone,
+                T::Error: Debug,
+            {
+                let pyobject = obj.clone().into_pyobject(py).unwrap().into_any();
+                let pystring = pyobject.as_borrowed().downcast::<PyString>().unwrap();
                 assert_eq!(pystring.to_string_lossy(), obj.as_ref().to_string_lossy());
                 let roundtripped_obj: OsString = pystring.extract().unwrap();
                 assert_eq!(obj.as_ref(), roundtripped_obj.as_os_str());

src/conversions/std/path.rs

@@ -44,6 +44,17 @@ impl<'py> IntoPyObject<'py> for &Path {
     }
 }
 
+impl<'py> IntoPyObject<'py> for &&Path {
+    type Target = PyString;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    #[inline]
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        (*self).into_pyobject(py)
+    }
+}
+
 impl<'a> ToPyObject for Cow<'a, Path> {
     #[inline]
     fn to_object(&self, py: Python<'_>) -> PyObject {
@@ -125,8 +136,10 @@ impl<'py> IntoPyObject<'py> for &PathBuf {
 
 #[cfg(test)]
 mod tests {
+    use crate::prelude::IntoPyObject;
     use crate::types::{PyAnyMethods, PyStringMethods};
-    use crate::{types::PyString, IntoPy, PyObject, Python, ToPyObject};
+    use crate::BoundObject;
+    use crate::{types::PyString, IntoPy, PyObject, Python};
     use std::borrow::Cow;
     use std::fmt::Debug;
     use std::path::{Path, PathBuf};
@@ -155,9 +168,13 @@ mod tests {
     #[test]
     fn test_topyobject_roundtrip() {
         Python::with_gil(|py| {
-            fn test_roundtrip<T: ToPyObject + AsRef<Path> + Debug>(py: Python<'_>, obj: T) {
-                let pyobject = obj.to_object(py);
-                let pystring = pyobject.downcast_bound::<PyString>(py).unwrap();
+            fn test_roundtrip<'py, T>(py: Python<'py>, obj: T)
+            where
+                T: IntoPyObject<'py> + AsRef<Path> + Debug + Clone,
+                T::Error: Debug,
+            {
+                let pyobject = obj.clone().into_pyobject(py).unwrap().into_any();
+                let pystring = pyobject.as_borrowed().downcast::<PyString>().unwrap();
                 assert_eq!(pystring.to_string_lossy(), obj.as_ref().to_string_lossy());
                 let roundtripped_obj: PathBuf = pystring.extract().unwrap();
                 assert_eq!(obj.as_ref(), roundtripped_obj.as_path());

src/pybacked.rs

@@ -1,13 +1,16 @@
 //! Contains types for working with Python objects that own the underlying data.
 
-use std::{ops::Deref, ptr::NonNull, sync::Arc};
+use std::{convert::Infallible, ops::Deref, ptr::NonNull, sync::Arc};
 
+#[allow(deprecated)]
+use crate::ToPyObject;
 use crate::{
+    prelude::IntoPyObject,
     types::{
         any::PyAnyMethods, bytearray::PyByteArrayMethods, bytes::PyBytesMethods,
         string::PyStringMethods, PyByteArray, PyBytes, PyString,
     },
-    Bound, DowncastError, FromPyObject, IntoPy, Py, PyAny, PyErr, PyResult, Python, ToPyObject,
+    Bound, DowncastError, FromPyObject, IntoPy, Py, PyAny, PyErr, PyResult, Python,
 };
 
 /// A wrapper around `str` where the storage is owned by a Python `bytes` or `str` object.
@@ -61,7 +64,7 @@ impl TryFrom<Bound<'_, PyString>> for PyBackedStr {
             let s = py_string.to_str()?;
             let data = NonNull::from(s);
             Ok(Self {
-                storage: py_string.as_any().to_owned().unbind(),
+                storage: py_string.into_any().unbind(),
                 data,
             })
         }
@@ -85,10 +88,11 @@ impl FromPyObject<'_> for PyBackedStr {
     }
 }
 
+#[allow(deprecated)]
 impl ToPyObject for PyBackedStr {
     #[cfg(any(Py_3_10, not(Py_LIMITED_API)))]
     fn to_object(&self, py: Python<'_>) -> Py<PyAny> {
-        self.storage.clone_ref(py)
+        self.storage.as_any().clone_ref(py)
     }
     #[cfg(not(any(Py_3_10, not(Py_LIMITED_API))))]
     fn to_object(&self, py: Python<'_>) -> Py<PyAny> {
@@ -99,14 +103,46 @@ impl ToPyObject for PyBackedStr {
 impl IntoPy<Py<PyAny>> for PyBackedStr {
     #[cfg(any(Py_3_10, not(Py_LIMITED_API)))]
     fn into_py(self, _py: Python<'_>) -> Py<PyAny> {
-        self.storage
+        self.storage.into_any()
     }
     #[cfg(not(any(Py_3_10, not(Py_LIMITED_API))))]
     fn into_py(self, py: Python<'_>) -> Py<PyAny> {
         PyString::new(py, &self).into_any().unbind()
     }
 }
 
+impl<'py> IntoPyObject<'py> for PyBackedStr {
+    type Target = PyAny;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    #[cfg(any(Py_3_10, not(Py_LIMITED_API)))]
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(self.storage.into_bound(py))
+    }
+
+    #[cfg(not(any(Py_3_10, not(Py_LIMITED_API))))]
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(PyString::new(py, &self).into_any())
+    }
+}
+
+impl<'py> IntoPyObject<'py> for &PyBackedStr {
+    type Target = PyAny;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    #[cfg(any(Py_3_10, not(Py_LIMITED_API)))]
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(self.storage.bind(py).to_owned())
+    }
+
+    #[cfg(not(any(Py_3_10, not(Py_LIMITED_API))))]
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(PyString::new(py, self).into_any())
+    }
+}
+
 /// A wrapper around `[u8]` where the storage is either owned by a Python `bytes` object, or a Rust `Box<[u8]>`.
 ///
 /// This type gives access to the underlying data via a `Deref` implementation.
@@ -203,6 +239,7 @@ impl FromPyObject<'_> for PyBackedBytes {
     }
 }
 
+#[allow(deprecated)]
 impl ToPyObject for PyBackedBytes {
     fn to_object(&self, py: Python<'_>) -> Py<PyAny> {
         match &self.storage {
@@ -221,6 +258,32 @@ impl IntoPy<Py<PyAny>> for PyBackedBytes {
     }
 }
 
+impl<'py> IntoPyObject<'py> for PyBackedBytes {
+    type Target = PyBytes;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        match self.storage {
+            PyBackedBytesStorage::Python(bytes) => Ok(bytes.into_bound(py)),
+            PyBackedBytesStorage::Rust(bytes) => Ok(PyBytes::new(py, &bytes)),
+        }
+    }
+}
+
+impl<'py> IntoPyObject<'py> for &PyBackedBytes {
+    type Target = PyBytes;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        match &self.storage {
+            PyBackedBytesStorage::Python(bytes) => Ok(bytes.bind(py).clone()),
+            PyBackedBytesStorage::Rust(bytes) => Ok(PyBytes::new(py, bytes)),
+        }
+    }
+}
+
 macro_rules! impl_traits {
     ($slf:ty, $equiv:ty) => {
         impl std::fmt::Debug for $slf {
@@ -297,6 +360,7 @@ use impl_traits;
 #[cfg(test)]
 mod test {
     use super::*;
+    use crate::prelude::IntoPyObject;
     use crate::Python;
     use std::collections::hash_map::DefaultHasher;
     use std::hash::{Hash, Hasher};
@@ -329,12 +393,12 @@ mod test {
     }
 
     #[test]
-    fn py_backed_str_to_object() {
+    fn py_backed_str_into_pyobject() {
         Python::with_gil(|py| {
             let orig_str = PyString::new(py, "hello");
             let py_backed_str = orig_str.extract::<PyBackedStr>().unwrap();
-            let new_str = py_backed_str.to_object(py);
-            assert_eq!(new_str.extract::<PyBackedStr>(py).unwrap(), "hello");
+            let new_str = py_backed_str.into_pyobject(py).unwrap();
+            assert_eq!(new_str.extract::<PyBackedStr>().unwrap(), "hello");
             #[cfg(any(Py_3_10, not(Py_LIMITED_API)))]
             assert!(new_str.is(&orig_str));
         });
@@ -389,25 +453,28 @@ mod test {
     }
 
     #[test]
-    fn py_backed_bytes_into_py() {
+    fn py_backed_bytes_into_pyobject() {
         Python::with_gil(|py| {
             let orig_bytes = PyBytes::new(py, b"abcde");
             let py_backed_bytes = PyBackedBytes::from(orig_bytes.clone());
-            assert!(py_backed_bytes.to_object(py).is(&orig_bytes));
+            assert!((&py_backed_bytes)
+                .into_pyobject(py)
+                .unwrap()
+                .is(&orig_bytes));
             assert!(py_backed_bytes.into_py(py).is(&orig_bytes));
         });
     }
 
     #[test]
-    fn rust_backed_bytes_into_py() {
+    fn rust_backed_bytes_into_pyobject() {
         Python::with_gil(|py| {
             let orig_bytes = PyByteArray::new(py, b"abcde");
             let rust_backed_bytes = PyBackedBytes::from(orig_bytes);
             assert!(matches!(
                 rust_backed_bytes.storage,
                 PyBackedBytesStorage::Rust(_)
             ));
-            let to_object = rust_backed_bytes.to_object(py).into_bound(py);
+            let to_object = (&rust_backed_bytes).into_pyobject(py).unwrap();
             assert!(&to_object.is_exact_instance_of::<PyBytes>());
             assert_eq!(&to_object.extract::<PyBackedBytes>().unwrap(), b"abcde");
             let into_py = rust_backed_bytes.into_py(py).into_bound(py);

src/types/slice.rs

@@ -1,8 +1,10 @@
 use crate::err::{PyErr, PyResult};
 use crate::ffi;
 use crate::ffi_ptr_ext::FfiPtrExt;
+use crate::prelude::IntoPyObject;
 use crate::types::any::PyAnyMethods;
 use crate::{Bound, PyAny, PyObject, Python, ToPyObject};
+use std::convert::Infallible;
 
 /// Represents a Python `slice`.
 ///
@@ -139,6 +141,26 @@ impl ToPyObject for PySliceIndices {
     }
 }
 
+impl<'py> IntoPyObject<'py> for PySliceIndices {
+    type Target = PySlice;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(PySlice::new(py, self.start, self.stop, self.step))
+    }
+}
+
+impl<'py> IntoPyObject<'py> for &PySliceIndices {
+    type Target = PySlice;
+    type Output = Bound<'py, Self::Target>;
+    type Error = Infallible;
+
+    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
+        Ok(PySlice::new(py, self.start, self.stop, self.step))
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

tests/ui/invalid_property_args.stderr

@@ -55,14 +55,14 @@ error[E0277]: `PhantomData<i32>` cannot be converted to a Python object
    = help: the trait `IntoPyObject<'_>` is not implemented for `PhantomData<i32>`, which is required by `for<'py> PhantomData<i32>: PyO3GetField<'py>`
    = note: implement `IntoPyObject` for `&PhantomData<i32>` or `IntoPyObject + Clone` for `PhantomData<i32>` to define the conversion
    = help: the following other types implement trait `IntoPyObject<'py>`:
+             &&OsStr
+             &&Path
              &&str
              &'a (T0, T1)
              &'a (T0, T1, T2)
              &'a (T0, T1, T2, T3)
              &'a (T0, T1, T2, T3, T4)
              &'a (T0, T1, T2, T3, T4, T5)
-             &'a (T0, T1, T2, T3, T4, T5, T6)
-             &'a (T0, T1, T2, T3, T4, T5, T6, T7)
            and $N others
    = note: required for `PhantomData<i32>` to implement `for<'py> PyO3GetField<'py>`
 note: required by a bound in `PyClassGetterGenerator::<ClassT, FieldT, Offset, false, false, false, false, false>::generate`

tests/ui/missing_intopy.stderr

@@ -8,14 +8,14 @@ error[E0277]: `Blah` cannot be converted to a Python object
   = note: if you do not wish to have a corresponding Python type, implement it manually
   = note: if you do not own `Blah` you can perform a manual conversion to one of the types in `pyo3::types::*`
   = help: the following other types implement trait `IntoPyObject<'py>`:
+            &&OsStr
+            &&Path
             &&str
             &'a (T0, T1)
             &'a (T0, T1, T2)
             &'a (T0, T1, T2, T3)
             &'a (T0, T1, T2, T3, T4)
             &'a (T0, T1, T2, T3, T4, T5)
-            &'a (T0, T1, T2, T3, T4, T5, T6)
-            &'a (T0, T1, T2, T3, T4, T5, T6, T7)
           and $N others
 note: required by a bound in `UnknownReturnType::<T>::wrap`
  --> src/impl_/wrap.rs