all: use trait upcasting

src/backends/dummy.rs

@@ -6,7 +6,7 @@ use {
         },
         video::drm::ConnectorType,
     },
-    std::{any::Any, error::Error, rc::Rc},
+    std::{error::Error, rc::Rc},
 };
 
 pub struct DummyBackend;
@@ -15,10 +15,6 @@ impl Backend for DummyBackend {
     fn run(self: Rc<Self>) -> SpawnedFuture<Result<(), Box<dyn Error>>> {
         unreachable!();
     }
-
-    fn into_any(self: Rc<Self>) -> Rc<dyn Any> {
-        self
-    }
 }
 
 pub struct DummyOutput {

src/backends/metal.rs

@@ -52,7 +52,6 @@ use {
     },
     bstr::ByteSlice,
     std::{
-        any::Any,
         cell::{Cell, RefCell},
         error::Error,
         ffi::{CStr, CString},
@@ -233,10 +232,6 @@ impl Backend for MetalBackend {
         }
     }
 
-    fn into_any(self: Rc<Self>) -> Rc<dyn Any> {
-        self
-    }
-
     fn switch_to(&self, vtnr: u32) {
         self.session.switch_to(vtnr, move |res| {
             if let Err(e) = res {

src/backends/x.rs

@@ -52,7 +52,6 @@ use {
     },
     jay_config::video::GfxApi,
     std::{
-        any::Any,
         borrow::Cow,
         cell::{Cell, RefCell},
         collections::VecDeque,
@@ -251,10 +250,6 @@ impl Backend for XBackend {
             Ok(())
         })
     }
-
-    fn into_any(self: Rc<Self>) -> Rc<dyn Any> {
-        self
-    }
 }
 
 pub struct XBackend {