1 files changed, 41 insertions, 0 deletions
diff --git a/src/display/drawing-item-ptr.h b/src/display/drawing-item-ptr.h
new file mode 100644
index 0000000..0707567
--- /dev/null
+++ b/src/display/drawing-item-ptr.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_DISPLAY_DRAWINGITEM_PTR_H
+#define INKSCAPE_DISPLAY_DRAWINGITEM_PTR_H
+
+#include <memory>
+#include <type_traits>
+
+namespace Inkscape { class DrawingItem; }
+
+/**
+ * Deleter object which calls the unlink() method of DrawingItem to schedule deferred destruction.
+ */
+struct UnlinkDeleter
+{
+    template <typename T>
+    void operator()(T *t)
+    {
+        static_assert(std::is_base_of_v<Inkscape::DrawingItem, T>);
+        t->unlink();
+    }
+};
+
+/**
+ * Smart pointer used by the Object Tree to hold items in the Display Tree, like std::unique_ptr.
+ *
+ * Upon deletion, the pointed-to object and its subtree will be destroyed immediately if not currently in use by a snapshot.
+ * Otherwise, destruction is deferred to after the snapshot is released.
+ */
+template <typename T>
+using DrawingItemPtr = std::unique_ptr<T, UnlinkDeleter>;
+
+/**
+ * Convienence function to create a DrawingItemPtr, like std::make_unique.
+ */
+template <typename T, typename... Args>
+auto make_drawingitem(Args&&... args)
+{
+    return DrawingItemPtr<T>(new T(std::forward<Args>(args)...));
+};
+
+#endif // INKSCAPE_DISPLAY_DRAWINGITEM_PTR_H