22.7. Bolt-ins: Coda

Whatever you call them, the bolt-in clearly represents a very powerful mechanism for significantly enhancing existing types; the most widely used framework for building COM components—ATL—is virtually all bolt-ins. In my own work I've found them to significantly enhance reuse. Where classic inheritance is able to provide modest reuse gains in related classes, and template, especially STL, techniques are able to provide reuse in implementation and algorithms, bolt-ins provide us with a way to combine the benefits of both.