typedef struct _asn1_obj_t {
	bool f_class:2;
	bool f_constr:1;
	uint8_t tag;
	size_t len;
	uint8_t *data;
} asn1_obj_t;


// some code
node_o->tag = tag & 0b11111;
node_o->f_constr = (tag>>5 & 1);
node_o->f_class = (tag>>6 & 0b11);