Avoid Casts

C++ Primer 4/e 在Expressions這裡還有一個忠告:『By using a cast, the programmer turns off or dampens normal type-checking (Section 2.3, p.44). We strongly recommend that programmers avoid casts and believe that most well-formed C++ programs can be written without relying on casts.

This advice is particularly important regarding use of reinterpret_casts. Such casts are always hazardous. Similarly, use of const_cast almost always indicates a design flaw. Properly designed systems should not need to cast away const. The other casts, static_cast and dynamic_cast, have their uses but should be needed infrequently. Every time you write a cast, you should think hard about whether you can achieve the same result in a different way. If the cast is unavoidable, errors can be mitigated by limiting the scope in which the cast value is used and by documenting all assumptions about the types involved.』