Trait PyFunctionArgument

pub trait PyFunctionArgument<'a, 'py>: Sized + 'a {
    type Holder: FunctionArgumentHolder;

    // Required method
    fn extract(
        obj: &'a Bound<'py, PyAny>,
        holder: &'a mut Self::Holder,
    ) -> PyResult<Self>;
}

A trait which is used to help PyO3 macros extract function arguments.

#[pyclass] structs need to extract as PyRef<T> and PyRefMut<T> wrappers rather than extracting &T and &mut T directly. The Holder type is used to hold these temporary wrappers - the way the macro is constructed, these wrappers will be dropped as soon as the pyfunction call ends.

There exists a trivial blanket implementation for T: FromPyObject with Holder = ().

Required Associated Types

type Holder: FunctionArgumentHolder

Required Methods

fn extract( obj: &'a Bound<'py, PyAny>, holder: &'a mut Self::Holder, ) -> PyResult<Self>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'a, 'py, T> PyFunctionArgument<'a, 'py> for Option<&'a Bound<'py, T>>

where T: PyTypeCheck + 'py,

type Holder = ()

fn extract(obj: &'a Bound<'py, PyAny>, _: &'a mut ()) -> PyResult<Self>

Implementors

impl<'a, 'py> PyFunctionArgument<'a, 'py> for &'a Coroutine

Available on crate feature experimental-async only.

type Holder = Option<PyRef<'py, Coroutine>>

impl<'a, 'py> PyFunctionArgument<'a, 'py> for &'a mut Coroutine

Available on crate feature experimental-async only.

type Holder = Option<PyRefMut<'py, Coroutine>>

impl<'a, 'py, T> PyFunctionArgument<'a, 'py> for &'a Bound<'py, T>

where T: PyTypeCheck + 'py,

type Holder = Option<()>

impl<'a, 'py, T> PyFunctionArgument<'a, 'py> for T

where T: FromPyObjectBound<'a, 'py> + 'a,

type Holder = ()