Fix build warnings (#14)

Author: ferjm

examples/image_slideshow.rs

@@ -118,7 +118,7 @@ where
         let delegate = delegate!("AppDelegate", {
             app: id = app,
             send: *const c_void = Box::into_raw(Box::new(send)) as *const c_void,
-            (applicationDidFinishLaunching:) => on_finish_launching as extern fn(&Object, Sel, id)
+            (applicationDidFinishLaunching:) => on_finish_launching as extern "C" fn(&Object, Sel, id)
         });
         let _: () = msg_send![app, setDelegate: delegate];
 

examples/video_inference.rs

@@ -93,7 +93,7 @@ where
         let delegate = delegate!("AppDelegate", {
             app: id = app,
             send: *const c_void = Box::into_raw(Box::new(send)) as *const c_void,
-            (applicationDidFinishLaunching:) => on_finish_launching as extern fn(&Object, Sel, id)
+            (applicationDidFinishLaunching:) => on_finish_launching as extern "C" fn(&Object, Sel, id)
         });
         app.setDelegate_(delegate);
 

src/video/meta.rs

@@ -28,7 +28,7 @@ unsafe impl Send for VideoAnomalyMeta {}
 unsafe impl Sync for VideoAnomalyMeta {}
 
 impl VideoClassificationMeta {
-    pub fn add(buffer: &mut gst::BufferRef) -> gst::MetaRefMut<Self, gst::meta::Standalone> {
+    pub fn add(buffer: &mut gst::BufferRef) -> gst::MetaRefMut<'_, Self, gst::meta::Standalone> {
         unsafe {
             // First add it with empty params
             let meta = gst::ffi::gst_buffer_add_meta(
@@ -57,7 +57,7 @@ impl VideoClassificationMeta {
 }
 
 impl VideoAnomalyMeta {
-    pub fn add(buffer: &mut gst::BufferRef) -> gst::MetaRefMut<Self, gst::meta::Standalone> {
+    pub fn add(buffer: &mut gst::BufferRef) -> gst::MetaRefMut<'_, Self, gst::meta::Standalone> {
         unsafe {
             // First add it with empty params
             let meta = gst::ffi::gst_buffer_add_meta(