Replace unneeded transmute calls with a safer alternative

gstreamer-app/src/app_sink.rs

@@ -17,7 +17,6 @@ use gst_app_sys;
 use gst_sys;
 use std::boxed::Box as Box_;
 use std::cell::RefCell;
-use std::mem::transmute;
 use std::panic;
 use std::ptr;
 use std::sync::atomic::{AtomicBool, Ordering};
@@ -295,7 +294,7 @@ impl AppSink {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"new-sample\0".as_ptr() as *const _,
-                Some(transmute(new_sample_trampoline::<F> as usize)),
+                Some(*(&new_sample_trampoline::<F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }
@@ -312,7 +311,7 @@ impl AppSink {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"new-preroll\0".as_ptr() as *const _,
-                Some(transmute(new_preroll_trampoline::<F> as usize)),
+                Some(*(&new_preroll_trampoline::<F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }

gstreamer-audio/src/audio_channel_position.rs

@@ -24,10 +24,8 @@ impl AudioChannelPosition {
         if pos < 0 {
             return 0;
         }
-        unsafe {
+
-            let val = mem::transmute::<gst_audio_sys::GstAudioChannelPosition, u32>(pos);
+        1 << (pos as u32)
-            1 << val
-        }
     }
 
     pub fn positions_to_mask(

gstreamer-base/src/aggregator.rs

@@ -100,9 +100,7 @@ impl<O: IsA<Aggregator>> AggregatorExtManual for O {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"notify::min-upstream-latency\0".as_ptr() as *const _,
-                Some(mem::transmute(
+                Some(*(&notify_min_upstream_latency_trampoline::<Self, F> as *const _ as *const _)),
-                    notify_min_upstream_latency_trampoline::<Self, F> as usize,
-                )),
                 Box_::into_raw(f),
             )
         }

gstreamer-pbutils/src/discoverer.rs

@@ -23,7 +23,6 @@ use gobject_sys;
 use gst_pbutils_sys;
 
 use std::boxed::Box as Box_;
-use std::mem::transmute;
 
 impl Discoverer {
     pub fn set_property_timeout(&self, timeout: gst::ClockTime) {
@@ -60,7 +59,7 @@ impl Discoverer {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"notify::timeout\0".as_ptr() as *const _,
-                Some(transmute(notify_timeout_trampoline::<Self, F> as usize)),
+                Some(*(&notify_timeout_trampoline::<Self, F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }

gstreamer-player/src/player.rs

@@ -15,7 +15,6 @@ use glib_sys;
 use gst;
 use gst_player_sys;
 use std::boxed::Box as Box_;
-use std::mem::transmute;
 use Player;
 use PlayerSignalDispatcher;
 use PlayerVideoRenderer;
@@ -72,7 +71,7 @@ impl Player {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"duration-changed\0".as_ptr() as *const _,
-                Some(transmute(duration_changed_trampoline::<F> as usize)),
+                Some(*(&duration_changed_trampoline::<F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }
@@ -88,7 +87,7 @@ impl Player {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"position-updated\0".as_ptr() as *const _,
-                Some(transmute(position_updated_trampoline::<F> as usize)),
+                Some(*(&position_updated_trampoline::<F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }
@@ -104,7 +103,7 @@ impl Player {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"seek-done\0".as_ptr() as *const _,
-                Some(transmute(seek_done_trampoline::<F> as usize)),
+                Some(*(&seek_done_trampoline::<F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }

gstreamer-rtsp-server/src/rtsp_auth.rs

@@ -6,7 +6,6 @@ use glib::translate::*;
 use gst_rtsp_server_sys;
 
 use std::boxed::Box as Box_;
-use std::mem::transmute;
 
 use RTSPAuth;
 use RTSPToken;
@@ -59,7 +58,7 @@ impl<O: IsA<RTSPAuth>> RTSPAuthExtManual for O {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"accept-certificate\0".as_ptr() as *const _,
-                Some(transmute(accept_certificate_trampoline::<Self, F> as usize)),
+                Some(*(&accept_certificate_trampoline::<Self, F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }

gstreamer-rtsp-server/src/rtsp_session_pool.rs

@@ -6,7 +6,6 @@ use glib_sys;
 use glib_sys::{gboolean, gpointer};
 use gst_rtsp_server_sys;
 use std::cell::RefCell;
-use std::mem::transmute;
 use RTSPSessionPool;
 
 unsafe extern "C" fn trampoline_watch<F: FnMut(&RTSPSessionPool) -> Continue + Send + 'static>(
@@ -49,7 +48,7 @@ impl<O: IsA<RTSPSessionPool>> RTSPSessionPoolExtManual for O {
             );
             glib_sys::g_source_set_callback(
                 source,
-                Some(transmute(trampoline_watch::<F> as usize)),
+                Some(*(&trampoline_watch::<F> as *const _ as *const _)),
                 into_raw_watch(func),
                 Some(destroy_closure_watch::<F>),
             );

gstreamer-rtsp-server/src/subclass/rtsp_media_factory.rs

@@ -273,7 +273,6 @@ where
     T: RTSPMediaFactoryImpl,
 {
     use once_cell::sync::Lazy;
-    use std::mem;
 
     static PIPELINE_QUARK: Lazy<glib::Quark> =
         Lazy::new(|| glib::Quark::from_string("gstreamer-rs-rtsp-media-pipeline"));
@@ -291,7 +290,7 @@ where
         media as *mut _,
         PIPELINE_QUARK.to_glib(),
         pipeline as *mut _,
-        Some(mem::transmute(gobject_sys::g_object_unref as usize)),
+        Some(*(&gobject_sys::g_object_unref as *const _ as *const _)),
     );
 
     pipeline as *mut _

gstreamer-video/src/functions.rs

@@ -14,7 +14,6 @@ use glib;
 use glib::translate::{from_glib_full, ToGlib, ToGlibPtr};
 use gst;
 
-use std::mem;
 use std::ptr;
 
 pub fn convert_sample(
@@ -106,7 +105,7 @@ unsafe fn convert_sample_async_unsafe<F>(
         timeout.to_glib(),
         Some(convert_sample_async_trampoline::<F>),
         Box::into_raw(user_data) as glib_sys::gpointer,
-        Some(mem::transmute(convert_sample_async_free::<F> as usize)),
+        Some(convert_sample_async_free::<F>),
     );
 }
 

gstreamer/src/bin.rs

@@ -22,7 +22,6 @@ use glib::GString;
 use gst_sys;
 
 use std::boxed::Box as Box_;
-use std::mem::transmute;
 use std::path;
 
 pub trait GstBinExtManual: 'static {
@@ -99,7 +98,7 @@ impl<O: IsA<Bin>> GstBinExtManual for O {
             connect_raw(
                 self.as_ptr() as *mut _,
                 b"do-latency\0".as_ptr() as *const _,
-                Some(transmute(do_latency_trampoline::<Self, F> as usize)),
+                Some(*(&do_latency_trampoline::<Self, F> as *const _ as *const _)),
                 Box_::into_raw(f),
             )
         }

gstreamer/src/bus.rs

@@ -16,7 +16,6 @@ use glib_sys;
 use glib_sys::{gboolean, gpointer};
 use gst_sys;
 use std::cell::RefCell;
-use std::mem::transmute;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
@@ -94,7 +93,7 @@ impl Bus {
             let source = gst_sys::gst_bus_create_watch(self.to_glib_none().0);
             glib_sys::g_source_set_callback(
                 source,
-                Some(transmute(trampoline_watch::<F> as usize)),
+                Some(*(&trampoline_watch::<F> as *const _ as *const _)),
                 into_raw_watch(func),
                 Some(destroy_closure_watch::<F>),
             );

gstreamer/src/iterator.rs

@@ -328,8 +328,7 @@ where
 
     let func = func as *const gobject_sys::GValue;
     let func = gobject_sys::g_value_get_boxed(func);
-    #[allow(clippy::transmute_ptr_to_ref)]
+    let func = &*(func as *const &(dyn Fn(T) -> bool + Send + Sync + 'static));
-    let func: &&(dyn Fn(T) -> bool + Send + Sync + 'static) = mem::transmute(func);
 
     let value = &*(value as *const glib::Value);
     let value = value