From cf6171a51fd8a9e58da72afe61651caacc84e311 Mon Sep 17 00:00:00 2001
From: Dorota Czaplejewicz <dorota.czaplejewicz@puri.sm>
Date: Tue, 6 Dec 2022 13:01:25 +0000
Subject: [PATCH] loops: Use Void for infinite loops

---
 src/actors/external/debug.rs       | 9 +++++----
 src/actors/external/mod.rs         | 5 ++++-
 src/actors/external/screensaver.rs | 5 +++--
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/actors/external/debug.rs b/src/actors/external/debug.rs
index bac4fa31..253d1d0e 100644
--- a/src/actors/external/debug.rs
+++ b/src/actors/external/debug.rs
@@ -3,12 +3,13 @@
  *
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
-use std::thread;
-use zbus::{Connection, ObjectServer, dbus_interface, fdo};
-
 use crate::main;
 use crate::state;
 
+use std::thread;
+use zbus::{Connection, ObjectServer, dbus_interface, fdo};
+
+use super::Void;
 
 use std::convert::TryInto;
 
@@ -37,7 +38,7 @@ impl Manager {
     }
 }
 
-fn start(mgr: Manager) -> Result<(), Box<dyn std::error::Error>> {
+fn start(mgr: Manager) -> Result<Void, Box<dyn std::error::Error>> {
     let connection = Connection::new_session()?;
     fdo::DBusProxy::new(&connection)?.request_name(
         "sm.puri.SqueekDebug",
diff --git a/src/actors/external/mod.rs b/src/actors/external/mod.rs
index 624d89da..d591386a 100644
--- a/src/actors/external/mod.rs
+++ b/src/actors/external/mod.rs
@@ -8,4 +8,7 @@
  
 pub mod debug;
 #[cfg(feature = "zbus_v1_5")]
-pub mod screensaver;
\ No newline at end of file
+pub mod screensaver;
+
+/// The uninhabited type. Cannot be created or returned; means "will never return" as return type. Useful for infinite loops.
+enum Void {}
\ No newline at end of file
diff --git a/src/actors/external/screensaver.rs b/src/actors/external/screensaver.rs
index bc496f2a..e0a5b338 100644
--- a/src/actors/external/screensaver.rs
+++ b/src/actors/external/screensaver.rs
@@ -3,10 +3,11 @@
  *
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
+use crate::logging;
 use std::thread;
 use zbus::{Connection, dbus_proxy};
 
-use crate::logging;
+use super::Void;
 
 
 #[derive(Debug)]
@@ -45,7 +46,7 @@ pub fn init(destination: Destination) {
     });
 }
 
-fn start(destination: Destination) -> Result<(), zbus::Error> {
+fn start(destination: Destination) -> Result<Void, zbus::Error> {
     let conn = Connection::new_session()?;
     let manager = ManagerProxy::new(&conn)?;