I don't believe an ORM is a zero cost abstraction either. Or most of OOP. The cost of implementing everything as a function is when one has to contend with the

I don't believe an ORM is a zero cost abstraction either. Or most of OOP. The cost of implementing everything as a function is when one has to contend with the fundamental machine architecture not dealing with everything as a function. This often leads to one of the highest cost abstractions out there, the Monad.