Make DeviceId/WindowId::dummy() safe (#3784)

src/changelog/unreleased.md

@@ -68,6 +68,7 @@ changelog entry.
 - Change signature of `EventLoop::run_app`, `EventLoopExtPumpEvents::pump_app_events` and
   `EventLoopExtRunOnDemand::run_app_on_demand` to accept a `impl ApplicationHandler` directly,
   instead of requiring a `&mut` reference to it.
+- `DeviceId::dummy()` and `WindowId::dummy()` are no longer marked `unsafe`.
 
 ### Removed
 

src/event.rs

@@ -440,16 +440,13 @@ pub struct DeviceId(pub(crate) platform_impl::DeviceId);
 impl DeviceId {
     /// Returns a dummy id, useful for unit testing.
     ///
-    /// # Safety
+    /// # Notes
     ///
     /// The only guarantee made about the return value of this function is that
     /// it will always be equal to itself and to future values returned by this function.
     /// No other guarantees are made. This may be equal to a real `DeviceId`.
-    ///
-    /// **Passing this into a winit function will result in undefined behavior.**
-    pub const unsafe fn dummy() -> Self {
-        #[allow(unused_unsafe)]
-        DeviceId(unsafe { platform_impl::DeviceId::dummy() })
+    pub const fn dummy() -> Self {
+        DeviceId(platform_impl::DeviceId::dummy())
     }
 }
 
@@ -1013,7 +1010,7 @@ mod tests {
         ($closure:expr) => {{
             #[allow(unused_mut)]
             let mut x = $closure;
-            let did = unsafe { event::DeviceId::dummy() };
+            let did = event::DeviceId::dummy();
 
             #[allow(deprecated)]
             {
@@ -1023,7 +1020,7 @@ mod tests {
                 use crate::window::WindowId;
 
                 // Mainline events.
-                let wid = unsafe { WindowId::dummy() };
+                let wid = WindowId::dummy();
                 x(NewEvents(event::StartCause::Init));
                 x(AboutToWait);
                 x(LoopExiting);
@@ -1138,7 +1135,7 @@ mod tests {
         });
         let _ = event::StartCause::Init.clone();
 
-        let did = unsafe { crate::event::DeviceId::dummy() }.clone();
+        let did = crate::event::DeviceId::dummy().clone();
         HashSet::new().insert(did);
         let mut set = [did, did, did];
         set.sort_unstable();

src/platform_impl/apple/appkit/mod.rs

@@ -35,7 +35,7 @@ pub(crate) use crate::platform_impl::Fullscreen;
 pub struct DeviceId;
 
 impl DeviceId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         DeviceId
     }
 }

src/platform_impl/apple/appkit/window.rs

@@ -74,7 +74,7 @@ impl Window {
 pub struct WindowId(pub usize);
 
 impl WindowId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         Self(0)
     }
 }

src/platform_impl/apple/uikit/mod.rs

@@ -31,7 +31,7 @@ pub(crate) use crate::platform_impl::Fullscreen;
 pub struct DeviceId;
 
 impl DeviceId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         DeviceId
     }
 }

src/platform_impl/apple/uikit/window.rs

@@ -699,7 +699,7 @@ pub struct WindowId {
 }
 
 impl WindowId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         WindowId { window: std::ptr::null_mut() }
     }
 }

src/platform_impl/linux/mod.rs

@@ -155,7 +155,7 @@ impl From<u64> for WindowId {
 }
 
 impl WindowId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         Self(0)
     }
 }
@@ -169,11 +169,11 @@ pub enum DeviceId {
 }
 
 impl DeviceId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         #[cfg(wayland_platform)]
-        return DeviceId::Wayland(unsafe { wayland::DeviceId::dummy() });
+        return DeviceId::Wayland(wayland::DeviceId::dummy());
         #[cfg(all(not(wayland_platform), x11_platform))]
-        return DeviceId::X(unsafe { x11::DeviceId::dummy() });
+        return DeviceId::X(x11::DeviceId::dummy());
     }
 }
 

src/platform_impl/linux/wayland/mod.rs

@@ -66,7 +66,7 @@ impl From<WaylandError> for OsError {
 pub struct DeviceId;
 
 impl DeviceId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         DeviceId
     }
 }

src/platform_impl/linux/x11/mod.rs

@@ -768,7 +768,7 @@ pub struct DeviceId(xinput::DeviceId);
 
 impl DeviceId {
     #[allow(unused)]
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         DeviceId(0)
     }
 }

src/platform_impl/web/device.rs

@@ -2,7 +2,7 @@
 pub struct DeviceId(pub i32);
 
 impl DeviceId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         Self(0)
     }
 }

src/platform_impl/web/event_loop/runner.rs

@@ -369,7 +369,7 @@ impl Shared {
                 }
 
                 runner.send_event(Event::DeviceEvent {
-                    device_id: RootDeviceId(unsafe { DeviceId::dummy() }),
+                    device_id: RootDeviceId(DeviceId::dummy()),
                     event: DeviceEvent::Key(RawKeyEvent {
                         physical_key: backend::event::key_code(&event),
                         state: ElementState::Pressed,
@@ -387,7 +387,7 @@ impl Shared {
                 }
 
                 runner.send_event(Event::DeviceEvent {
-                    device_id: RootDeviceId(unsafe { DeviceId::dummy() }),
+                    device_id: RootDeviceId(DeviceId::dummy()),
                     event: DeviceEvent::Key(RawKeyEvent {
                         physical_key: backend::event::key_code(&event),
                         state: ElementState::Released,

src/platform_impl/web/event_loop/window_target.rs

@@ -150,7 +150,7 @@ impl ActiveEventLoop {
                     }
                 });
 
-                let device_id = RootDeviceId(unsafe { DeviceId::dummy() });
+                let device_id = RootDeviceId(DeviceId::dummy());
 
                 runner.send_events(
                     iter::once(Event::WindowEvent {
@@ -186,7 +186,7 @@ impl ActiveEventLoop {
                     }
                 });
 
-                let device_id = RootDeviceId(unsafe { DeviceId::dummy() });
+                let device_id = RootDeviceId(DeviceId::dummy());
 
                 runner.send_events(
                     iter::once(Event::WindowEvent {

src/platform_impl/web/window.rs

@@ -431,7 +431,7 @@ impl Drop for Inner {
 pub struct WindowId(pub(crate) u32);
 
 impl WindowId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         Self(0)
     }
 }

src/platform_impl/windows/mod.rs

@@ -64,7 +64,7 @@ unsafe impl Sync for PlatformSpecificWindowAttributes {}
 pub struct DeviceId(u32);
 
 impl DeviceId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         DeviceId(0)
     }
 }
@@ -100,7 +100,7 @@ unsafe impl Send for WindowId {}
 unsafe impl Sync for WindowId {}
 
 impl WindowId {
-    pub const unsafe fn dummy() -> Self {
+    pub const fn dummy() -> Self {
         WindowId(0)
     }
 }

src/window.rs

@@ -70,16 +70,13 @@ pub struct WindowId(pub(crate) platform_impl::WindowId);
 impl WindowId {
     /// Returns a dummy id, useful for unit testing.
     ///
-    /// # Safety
+    /// # Notes
     ///
     /// The only guarantee made about the return value of this function is that
     /// it will always be equal to itself and to future values returned by this function.
     /// No other guarantees are made. This may be equal to a real [`WindowId`].
-    ///
-    /// **Passing this into a winit function will result in undefined behavior.**
-    pub const unsafe fn dummy() -> Self {
-        #[allow(unused_unsafe)]
-        WindowId(unsafe { platform_impl::WindowId::dummy() })
+    pub const fn dummy() -> Self {
+        WindowId(platform_impl::WindowId::dummy())
     }
 }