Struct pyo3::pycell::PyRef [−][src]
pub struct PyRef<'p, T: PyClass> { /* fields omitted */ }
Expand description
A wrapper type for an immutably borrowed value from a PyCell
<T>
.
See the PyCell
documentation for more information.
Examples
You can use PyRef
as an alternative to a &self
receiver when
- you need to access the pointer of the
PyCell
, or - you want to get a super class.
#[pyclass(subclass)]
struct Parent {
basename: &'static str,
}
#[pyclass(extends=Parent)]
struct Child {
name: &'static str,
}
#[pymethods]
impl Child {
#[new]
fn new() -> (Self, Parent) {
(Child { name: "Caterpillar" }, Parent { basename: "Butterfly" })
}
fn format(slf: PyRef<Self>) -> String {
// We can get *mut ffi::PyObject from PyRef
use pyo3::AsPyPointer;
let refcnt = unsafe { pyo3::ffi::Py_REFCNT(slf.as_ptr()) };
// We can get &Self::BaseType by as_ref
let basename = slf.as_ref().basename;
format!("{}(base: {}, cnt: {})", slf.name, basename, refcnt)
}
}
See the module-level documentation for more information.
Implementations
Gets a PyRef<T::BaseType>
.
While as_ref()
returns a reference of type &T::BaseType
, this cannot be
used to get the base of T::BaseType
.
But with the help of this method, you can get hold of instances of the super-superclass when needed.
Examples
#[pyclass(subclass)]
struct Base1 {
name1: &'static str,
}
#[pyclass(extends=Base1, subclass)]
struct Base2 {
name2: &'static str,
}
#[pyclass(extends=Base2)]
struct Sub {
name3: &'static str,
}
#[pymethods]
impl Sub {
#[new]
fn new() -> PyClassInitializer<Self> {
PyClassInitializer::from(Base1 { name1: "base1" })
.add_subclass(Base2 { name2: "base2" })
.add_subclass(Self { name3: "sub" })
}
fn name(slf: PyRef<Self>) -> String {
let subname = slf.name3;
let super_ = slf.into_super();
format!("{} {} {}", super_.as_ref().name1, super_.name2, subname)
}
}