Why std::function is too slow is CPU can't utilize instruction reordering?

While i develop my project, I found std::function is really slow.
So I tried to know why it's really slow.
But I couldn't find obvious cause of that.

I think What Cpu can't utilize instruction reordering optimization and cpu pipeline because it doesn't know which function is called is cause of poor performance.
It makes memory stall and slow performance....

Am I right???