1 files changed, 28 insertions, 0 deletions
diff --git a/vendor/windows-core/src/weak.rs b/vendor/windows-core/src/weak.rs
new file mode 100644
index 00000000..f89a2315
--- /dev/null
+++ b/vendor/windows-core/src/weak.rs
@@ -0,0 +1,28 @@
+use super::*;
+use core::marker::PhantomData;
+
+/// `Weak` holds a non-owning reference to an object.
+#[derive(Clone, PartialEq, Eq, Default)]
+pub struct Weak<I: Interface>(Option<imp::IWeakReference>, PhantomData<I>);
+
+impl<I: Interface> Weak<I> {
+    /// Creates a new `Weak` object without any backing object.
+    pub const fn new() -> Self {
+        Self(None, PhantomData)
+    }
+
+    /// Attempts to upgrade the weak reference to a strong reference.
+    pub fn upgrade(&self) -> Option<I> {
+        self.0
+            .as_ref()
+            .and_then(|inner| unsafe { inner.Resolve().ok() })
+    }
+
+    pub(crate) fn downgrade(source: &imp::IWeakReferenceSource) -> Result<Self> {
+        let reference = unsafe { source.GetWeakReference().ok() };
+        Ok(Self(reference, PhantomData))
+    }
+}
+
+unsafe impl<I: Interface> Send for Weak<I> {}
+unsafe impl<I: Interface> Sync for Weak<I> {}