x11: add nested x11 backend

src/utils.rs

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+use smithay::reexports::wayland_server::{Global, Interface, Resource};
+use std::convert::{AsRef, From};
+
+pub struct GlobalDrop<I: Interface + AsRef<Resource<I>> + From<Resource<I>>>(Option<Global<I>>);
+
+impl<I: Interface + AsRef<Resource<I>> + From<Resource<I>>> From<Global<I>> for GlobalDrop<I> {
+    fn from(g: Global<I>) -> GlobalDrop<I> {
+        GlobalDrop(Some(g))
+    }
+}
+
+impl<I: Interface + AsRef<Resource<I>> + From<Resource<I>>> Drop for GlobalDrop<I> {
+    fn drop(&mut self) {
+        if let Some(global) = self.0.take() {
+            global.destroy();
+        }
+    }
+}