fn default_struct_substructure(
cx: &ExtCtxt<'_>,
trait_span: Span,
substr: &Substructure<'_>,
summary: &StaticFields<'_>,
) -> BlockOrExprfn default_struct_substructure(
cx: &ExtCtxt<'_>,
trait_span: Span,
substr: &Substructure<'_>,
summary: &StaticFields<'_>,
) -> BlockOrExpr