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use crate::*;
use bindings::Windows::Win32::System::WinRT::{IWeakReference, IWeakReferenceSource};
use std::marker::PhantomData;
#[derive(Clone, PartialEq, Eq, Default, Debug)]
pub struct Weak<I: Interface>(Option<IWeakReference>, PhantomData<I>);
impl<I: Interface> Weak<I> {
pub fn new() -> Self {
Self(None, PhantomData)
}
pub fn upgrade(&self) -> Option<I> {
self.0.as_ref().and_then(|inner| unsafe {
let mut result = None;
let _ = (inner.vtable().3)(
std::mem::transmute_copy(inner),
&I::IID,
&mut result as *mut _ as _,
);
result
})
}
pub(crate) fn downgrade(source: &IWeakReferenceSource) -> Result<Self> {
let reference = unsafe { source.GetWeakReference().ok() };
Ok(Self(reference, PhantomData))
}
}