[pjmlp]

First of all, it is C++ OOP style, Java cloned C++, not the other way around.

Secondly, all major surviving C++ GUI frameworks are still using the same style.

Best practice according to well known folks in the computing industry, with more impact than any of us will ever have on our lifetimes.

[mebassett]

I think the main point here is that while this style might make sense for a GUI framework it's not so great for a numerical library like this.

For example: my library is really slow.

[pjmlp]

And instead of blaming OOP, have you actually used a profiler?

[tightbookkeeper]

Are you suggesting that many individual allocations and virtual dispatch are not impactful, or just advocating use of a profiler?

Once again, the context of this thread is someone taking an interest in C++ to write fast autodiff code.