MPI-I-2001-1-004

Geometric algorithms are based on geometric objects such as points, lines and circles. The term \textit{kernel\/} refers to a collection of representations for constant-size geometric objects and operations on these representations. This paper describes how such a geometry kernel can be designed and implemented in C++, having special emphasis on adaptability, extensibility and efficiency. We achieve these goals following the generic programming paradigm and using templates as our tools. These ideas are realized and tested in \cgal~\cite{svy-cgal}, the Computational Geometry Algorithms Library.