Remove ZeroizeOnDrop implementation for #[zeroize(drop)] (#715)

Author: daxpedda

zeroize/derive/src/lib.rs

@@ -317,17 +317,13 @@ fn derive_zeroize_with_drop(s: synstructure::Structure<'_>) -> TokenStream {
         }
     });
 
-    let zeroize_on_drop_impl = impl_zeroize_on_drop(&s);
-
     let zeroize_impl = derive_zeroize_without_drop(s);
 
     quote! {
         #zeroize_impl
 
         #[doc(hidden)]
         #drop_impl
-
-        #zeroize_on_drop_impl
     }
 }
 
@@ -418,12 +414,6 @@ mod tests {
                         }
                     }
                 };
-                #[allow(non_upper_case_globals)]
-                #[doc(hidden)]
-                const _DERIVE_zeroize_ZeroizeOnDrop_FOR_Z: () = {
-                    extern crate zeroize;
-                    impl zeroize::ZeroizeOnDrop for Z {}
-                };
             }
             no_build // tests the code compiles are in the `zeroize` crate
         }