{"ast_node_type":"other","tokens":[{"end":55,"kind":"keyword","start":0,"text":"None"}]}
            None => Err(CastError::UnknownExprPtrKind),
        match fcx.pointer_kind(m_expr.ty, self.span)? {
            Some(PointerKind::Thin) => Ok(CastKind::PtrAddrCast),