[FpUser]

"you have to start with interesting algorithms. Only when you understand them well, can you come up with an interface that will let them work"

I did just that in my old days when there was no real OOP around. And said interface included data structures that along with regular fields also had pointers to functions with some extra scaffolding around it. I did all of it on my own without having any slightest ideas about OOP. Luckily the actual OOP compilers came out soon.

So here's to you Mr. Stepanov.