refactor: remove TriviallyDrop trait

Signed-off-by: Yaroslav Bolyukin <iam@lach.pw>

Author: CertainLach

gc/src/lib.rs

@@ -35,7 +35,7 @@ pub use gc_derive::{Finalize, Trace};
 // We re-export the Trace method, as well as some useful internal methods for
 // managing collections or configuring the garbage collector.
 pub use crate::gc::{finalizer_safe, force_collect};
-pub use crate::trace::{Finalize, Trace, TriviallyDrop};
+pub use crate::trace::{Finalize, Trace};
 
 ////////
 // Gc //

gc/src/trace.rs

@@ -17,12 +17,6 @@ pub trait Finalize {
     fn finalize(&self) {}
 }
 
-/// Ensures type has no custom Drop implementation, without implementing it itself
-/// In case of Drop implementation present, obscure compilation error will be raised
-pub unsafe trait TriviallyDrop {
-    unsafe fn guard(self);
-}
-
 #[cfg(feature = "nightly")]
 impl<T: ?Sized> Finalize for T {
     // XXX: Should this function somehow tell its caller (which is presumably

gc_derive/src/lib.rs

@@ -76,25 +76,19 @@ fn derive_trace(mut s: Structure<'_>) -> proc_macro2::TokenStream {
             #drop_impl
         }
     } else {
-        let finalize_impl = derive_finalize(s.clone());
-
         s.bind_with(|_| BindStyle::Move);
-        let trivially_drop_body = s.each(|bi| quote!(drop(#bi)));
-
-        let trivially_drop_impl = s.unsafe_bound_impl(
-            quote!(::gc::TriviallyDrop),
+        let trivially_drop_body = s.each(|_| quote! {});
+        let finalize_impl = s.bound_impl(
+            quote!(::gc::Finalize),
             quote!(
-                unsafe fn guard(self) {
-                    match self {
-                        #trivially_drop_body
-                    }
+                fn finalize(&self) {
+                    let _trivially_drop = |t: Self| match t { #trivially_drop_body };
                 }
             ),
         );
 
         quote! {
             #trace_impl
-            #trivially_drop_impl
             #finalize_impl
         }
     }