message: Mark generated Dupe implementation inline
  Summary: This change seems to make only a little perf difference unlike previous diff
diff: @@ -43,6 +43,7 @@ fn derive_dupe_explicit(
  let body = duplicate_impl(&input.data, &quote! { dupe::Dupe::dupe });
  let gen = quote! {
  impl #impl_generics dupe::Dupe for #name #ty_generics #where_clause {
  + #[inline]
  fn dupe(&self) -> Self {
  #body
  }
  