I don’t have one log() call in my code. I have 1000 different ones logging 1000 different things. How does what you are trying scale?

So you won’t need one function pointer, you need at least 2,000. Enjoy. Especially when the next developer runs to your boss and says “I can’t believe…”

There is a perfectly fine solution that works very well and doesnt produce any clutter in your source code. Why exactly don’t you want to use it?