1 files changed, 31 insertions, 0 deletions
diff --git a/vendor/windows-core/src/out_ref.rs b/vendor/windows-core/src/out_ref.rs
new file mode 100644
index 00000000..24ba06ca
--- /dev/null
+++ b/vendor/windows-core/src/out_ref.rs
@@ -0,0 +1,31 @@
+use super::*;
+
+/// A borrowed type with the same memory layout as the type itself that can be used to construct ABI-compatible function signatures.
+///
+/// This is a mutable version of [Ref] meant to support out parameters.
+#[repr(transparent)]
+pub struct OutRef<'a, T: Type<T>>(*mut T::Abi, core::marker::PhantomData<&'a T>);
+
+impl<T: Type<T>> OutRef<'_, T> {
+    /// Returns `true` if the argument is null.
+    pub fn is_null(&self) -> bool {
+        self.0.is_null()
+    }
+
+    /// Overwrites a memory location with the given value without reading or dropping the old value.
+    pub fn write(self, value: T::Default) -> Result<()> {
+        if self.0.is_null() {
+            Err(Error::from_hresult(imp::E_POINTER))
+        } else {
+            unsafe { *self.0 = core::mem::transmute_copy(&value) }
+            core::mem::forget(value);
+            Ok(())
+        }
+    }
+}
+
+impl<'a, T: Type<T>> From<&'a mut T::Default> for OutRef<'a, T> {
+    fn from(from: &'a mut T::Default) -> Self {
+        unsafe { core::mem::transmute(from) }
+    }
+}