pyo3/conversions/std/
option.rs

1use crate::{
2    conversion::IntoPyObject, ffi, types::any::PyAnyMethods, AsPyPointer, Bound, BoundObject,
3    FromPyObject, PyAny, PyObject, PyResult, Python,
4};
5
6/// `Option::Some<T>` is converted like `T`.
7/// `Option::None` is converted to Python `None`.
8#[allow(deprecated)]
9impl<T> crate::ToPyObject for Option<T>
10where
11    T: crate::ToPyObject,
12{
13    fn to_object(&self, py: Python<'_>) -> PyObject {
14        self.as_ref()
15            .map_or_else(|| py.None(), |val| val.to_object(py))
16    }
17}
18
19#[allow(deprecated)]
20impl<T> crate::IntoPy<PyObject> for Option<T>
21where
22    T: crate::IntoPy<PyObject>,
23{
24    fn into_py(self, py: Python<'_>) -> PyObject {
25        self.map_or_else(|| py.None(), |val| val.into_py(py))
26    }
27}
28
29impl<'py, T> IntoPyObject<'py> for Option<T>
30where
31    T: IntoPyObject<'py>,
32{
33    type Target = PyAny;
34    type Output = Bound<'py, Self::Target>;
35    type Error = T::Error;
36
37    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
38        self.map_or_else(
39            || Ok(py.None().into_bound(py)),
40            |val| {
41                val.into_pyobject(py)
42                    .map(BoundObject::into_any)
43                    .map(BoundObject::into_bound)
44            },
45        )
46    }
47}
48
49impl<'a, 'py, T> IntoPyObject<'py> for &'a Option<T>
50where
51    &'a T: IntoPyObject<'py>,
52{
53    type Target = PyAny;
54    type Output = Bound<'py, Self::Target>;
55    type Error = <&'a T as IntoPyObject<'py>>::Error;
56
57    #[inline]
58    fn into_pyobject(self, py: Python<'py>) -> Result<Self::Output, Self::Error> {
59        self.as_ref().into_pyobject(py)
60    }
61}
62
63impl<'py, T> FromPyObject<'py> for Option<T>
64where
65    T: FromPyObject<'py>,
66{
67    fn extract_bound(obj: &Bound<'py, PyAny>) -> PyResult<Self> {
68        if obj.is_none() {
69            Ok(None)
70        } else {
71            obj.extract().map(Some)
72        }
73    }
74}
75
76/// Convert `None` into a null pointer.
77unsafe impl<T> AsPyPointer for Option<T>
78where
79    T: AsPyPointer,
80{
81    #[inline]
82    fn as_ptr(&self) -> *mut ffi::PyObject {
83        self.as_ref()
84            .map_or_else(std::ptr::null_mut, |t| t.as_ptr())
85    }
86}
87
88#[cfg(test)]
89mod tests {
90    use crate::{PyObject, Python};
91
92    #[test]
93    fn test_option_as_ptr() {
94        Python::with_gil(|py| {
95            use crate::AsPyPointer;
96            let mut option: Option<PyObject> = None;
97            assert_eq!(option.as_ptr(), std::ptr::null_mut());
98
99            let none = py.None();
100            option = Some(none.clone_ref(py));
101
102            let ref_cnt = none.get_refcnt(py);
103            assert_eq!(option.as_ptr(), none.as_ptr());
104
105            // Ensure ref count not changed by as_ptr call
106            assert_eq!(none.get_refcnt(py), ref_cnt);
107        });
108    }
109}
pyo3/conversions/std/option.rs

pyo3/conversions/std/
option.rs
