The days when you can reason about performance by looking at function signatures are, in my opinion, long gone. I can count on one hand the number of times tha

The days when you can reason about performance by looking at function signatures are, in my opinion, long gone. I can count on one hand the number of times that I thought that changing the function signature of a few methods was going to impact whole application performance. Every time, it was in a low-level function that was called all over the place. Or, more to the point, I dug into function signatures when evidence pointed me there. I can't even begin to list all of the other problems I worry about that actually do impact whole application performance on a regular basis.