Reference里的前三个分别介绍了CRTP的概念、常见用法、以及实现。最后一个为StackOverflow里的高票答案，简单易懂地诠释了CRTP的基本概念以及一些常见用法。都是好文章，值得一看。
Reference:
The Curiously Recurring Template Pattern (CRTP)
What the Curiously Recurring Template Pattern can bring to your code
An Implementation Helper For The Curiously Recurring Template Pattern
StackOverflow: What is the curiously recurring template pattern (CRTP)?