macro_rules! default_deserializer { ($spec_ty: ident { }) => { ... }; ($spec_ty: ident { $($fname: ident: $ftyp: ty ),+ }) => { ... }; }
macro_rules! default_deserializer { ($spec_ty: ident { }) => { ... }; ($spec_ty: ident { $($fname: ident: $ftyp: ty ),+ }) => { ... }; }