This is why you want a two-tiered API: High level and low level. The high level API chooses a static trade-off in performance, size, etc for the 80% case, and t

This is why you want a two-tiered API: High level and low level. The high level API chooses a static trade-off in performance, size, etc for the 80% case, and the low level API gives more explicit control over what's going on. In this case, you could create the function normalized() for the 80% case, and normalize_in_place() for users who need to optimize this path (choosing to take on the extra responsibilities that come with it).