update DefaultNoBound derive macro (#12723)

fix derive for empty enums

Update derive & ui tests

clean up

Apply suggestions from code review

Co-authored-by: Bastian Köcher <git@kchr.de>

rename variable

formatting & clippy

formatting

Co-authored-by: parity-processbot <>

substrate/frame/support/procedural/src/lib.rs

@@ -582,7 +582,7 @@ pub fn derive_eq_no_bound(input: TokenStream) -> TokenStream {
 }
 
 /// derive `Default` but do no bound any generic. Docs are at `frame_support::DefaultNoBound`.
-#[proc_macro_derive(DefaultNoBound)]
+#[proc_macro_derive(DefaultNoBound, attributes(default))]
 pub fn derive_default_no_bound(input: TokenStream) -> TokenStream {
 	default_no_bound::derive_default_no_bound(input)
 }