-void answer_add_bucket(bucket_t bucket, answer_t answer);
-unsigned int answer_contains(answer_t answer, unsigned int id);
-unsigned int answer_destination_found(answer_t answer);
+void answer_add_bucket(const_bucket_t bucket, answer_t answer);
+unsigned int answer_contains(const_answer_t answer, unsigned int id);
+unsigned int answer_destination_found(const_answer_t answer);