1. 最常见情况
2. Reference to Const
3. Pointers and Const
4. Const的不同Level
5. const与Class
5.1 const member function - 函数的末尾有const
5.2 返回值使用const
Reference
- https://isocpp.org/wiki/faq/const-correctness
- C++ Primier 5th - Chp. 2.4