Use the Pimpl Idiom to Reduce Compilation Time and Enhance Encapsulation

ong compilation time is an issue of concern for many large-scale C++ projects. In some cases, a typical build cycle takes up a whole night or an entire weekend. This problem is aggravated by the fact that changes in the implementation details of a single infrastructure class trigger a wholesale recompilation of numerous classes that refer to the modified class. This solution will show you how to apply the Pimpl idiom to reduce compile-time dependencies, and thus reduce compilation time. Another benefit of using this technique is a higher level of encapsulation.

How can you avoid a wholesale recompilation when a change in the implementation details of a frequently-used class has taken place?

Use the Pimpl idiom, also known as the compiler-firewall idiom.