Fix clang builds.

mbucko · mbucko · commit 68771fce1852 · 2024-07-21T14:45:07.000-04:00
diff --git a/data/languages/cpp/singletreenode.h b/data/languages/cpp/singletreenode.h
@@ -3,7 +3,9 @@
 
 #include "treenode.h"
 
-struct SingleTreeNode : public TreeNode { };
+struct SingleTreeNode : public TreeNode {
+    using TreeNode::TreeNode;
+};
 
 static_assert(sizeof(SingleTreeNode) == sizeof(TreeNode),
               "SingleTreeNode is not the same size as TreeNode");
