Function rustc_builtin_macros::deriving::decodable::decode_static_fields

fn decode_static_fields<F>(
    cx: &mut ExtCtxt<'_>, 
    trait_span: Span, 
    outer_pat_path: Path, 
    fields: &StaticFields, 
    getarg: F
) -> P<Expr> where
    F: FnMut(&mut ExtCtxt<'_>, Span, Symbol, usize) -> P<Expr>, 

Creates a decoder for a single enum variant/struct:

• outer_pat_path is the path to this enum variant/struct
• getarg should retrieve the usize-th field with name @str.