c++中增加虚类可以减少编译时间?

[emmix]

请问下面这段话怎么理解:

An abstract class is purely an interface to the implemnetaions supplied as classes derived from it. This limits the amount of recompilation necessary after a change as well as the aamount of information necessary to compile an average piece of code. By decreasing the couping between a use and an implenenter, abstract classes provide an answer to people complaing about long comile times and also serve libray provides.

[hhyttppd]

这段话的大概的意思当你只修改了接口的实现，而没有改变接口本身，使用接口的客户代码不需要重新编译，从而缩短了编译时间。这应该很好理解吧？

[chenzhp]

一个抽象类纯粹就是为了给它的派生类提供接口。接口使得客户和提供者之间的分工明确，降低了再重新改变了代码后的再次编译时间。