Static header as sentinel

Writing code to handle dynamic data structures might seem to be an easy task, but write an efficient, readable and maintainable code is not such a simple task. In this short note we investigate some problems in developing code for handling dynamic data structures, and we propose techniques to overcome them. We take into account the interesting method proposed by Qiu in SIGPLAN Notices [3]. Many authors have addressed the problem of handling dynamic data structures by suggesting several clever tricks to simplify dynamic data structures management [4, 2] and to avoid the non-uniform behavior of empty data structures, and access to the first and the last element. In particular, the use of data sentinels and dummy headers makes the implementation more orthogonal and easy to maintain. The cost is a slightly increased size in space which is negligible when compared with the benefits produced.