Question

I know that dynamic_cast have runtime check and therefor consider safer (can return null pointer on failure) but slower then static_cast. but how bad is the overhead between the two?

should I realy consider use static_cast in loops for performance issues in regular large projects? or the difference is minor and only relevant for special real-time programs.

Answer 1

Did you profile it?

The rule is:

• Use static_cast when you know that the target type is valid.
• Use dynamic_cast when you’re not sure, and you need the program to look up the object’s runtime type for you.

It’s as simple as that. All other considerations are secondary.