C++ Coding Standards: 101 Rules, Guidelines, and Best Practices

93. Avoid using static_cast on pointers

Summary

Pointers to dynamic objects don’t static_cast: Safe alternatives range from using dynamic_cast to refactoring to redesigning.

Discussion

Consider replacing uses of static_cast with its more powerful relative dynamic_cast, and then you won’t have to remember when static_cast is safe and when it’s dangerous. Although dynamic_cast can be slightly less efficient, it also detects illegal casting (and don’t forget Item 8). Using static_cast instead of dynamic_cast is like eliminating the stairs night-light, risking a broken leg to save 90 cents a year.

Prefer to design away downcasting: Refactor or redesign your code so that it isn’t needed. If you see that you are passing a Base to a function that ...