Performance hit from C++ style casts?

Question

I am new to C++ style casts and I am worried that using C++ style casts will ruin the performance of my application because I have a real-time-critical dead

Answer 1

When using dynamic_cast several checks are made during runtime to prevent you from doing something stupid (more at the GCC mailing list), the cost of one dynamic_cast depends on how many classes are affected, what classes are affected, etc.
If you're really sure the cast is safe, you can still use reinterpret_cast.