Using Chains to Free Library Code

摘要

Library writers produce code that can be applied to any number of problems. It is not the role of the library to anticipate all of the ways in which it will be used, but instead to liberate programmers to use the library for any appropriate application. Both Loki and Boost are excellent examples of this principle. They can be used to solve problems that their authors never imagined. But occasionally, library writers find that C++ syntax limits the application of their library. A function has to be overloaded for a variable number of parameters, or a template needs to be specialized for an indeterminate number of types. When faced with these challenges, you're forced to choose an arbitrary limit.