1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/rust/wpf-gpu-raster/src/nullable_ref.rs b/third_party/rust/wpf-gpu-raster/src/nullable_ref.rs
new file mode 100644
index 0000000000..1e8389e5b7
--- /dev/null
+++ b/third_party/rust/wpf-gpu-raster/src/nullable_ref.rs
@@ -0,0 +1,53 @@
+use std::{marker::PhantomData, ops::Deref};
+
+pub struct Ref<'a, T> {
+    ptr: *const T,
+    _phantom: PhantomData<&'a T>
+}
+
+impl<'a, T> Copy for Ref<'a, T> { }
+
+impl<'a, T> Clone for Ref<'a, T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<'a, T> Ref<'a, T> {
+    pub fn new(p: &'a T) -> Self {
+        Ref { ptr: p as *const T, _phantom: PhantomData}
+    }
+    pub unsafe fn null() -> Self {
+        Ref { ptr: std::ptr::null(), _phantom: PhantomData}
+    }
+    pub fn is_null(&self) -> bool {
+        self.ptr.is_null()
+    }
+    pub fn get_ref(self) -> &'a T {
+        unsafe { &*self.ptr }
+    }
+}
+
+impl<'a, T> PartialEq for Ref<'a, T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.ptr == other.ptr && self._phantom == other._phantom
+    }
+}
+
+impl<'a, T> PartialOrd for Ref<'a, T> {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        match self.ptr.partial_cmp(&other.ptr) {
+            Some(core::cmp::Ordering::Equal) => {}
+            ord => return ord,
+        }
+        self._phantom.partial_cmp(&other._phantom)
+    }
+}
+
+impl<'a, T> Deref for Ref<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.ptr }
+    }
+}
+\ No newline at end of file