Much of this is very compiler dependent. For example, Java's compiler is generally able to perform more aggressive optimisations, and even virtual calls are oft

Much of this is very compiler dependent. For example, Java's compiler is generally able to perform more aggressive optimisations, and even virtual calls are often, and even usually, inlined (so if at a particular call-site only one shape is encountered, there won't even be a branch, just straight inline code, and if there are only two or three shapes, the call would compile to a branch; only if there are more, i.e. a "megamorphic" call site will a vtable indirection actually take place). There is no general way of concluding that a virtual call is more or less costly than a branch, but the best approximation is "about the same." Having said that, even Java now encourages programmers to use algebraic data types when "programming in the small", and OOP/encapsulation at module boundaries: https://www.infoq.com/articles/data-oriented-programming-java/ https://www.infoq.com/articles/data-oriented-programming-jav... though not for performance reasons. My point being is that the "best practice" recommendations for mainstream language does change.