This argument is brought up a lot against using opportunity cost for private projects, but I don't buy it

If you are dedicating a considerable amount of time on a project, there is of cause opportunity cost, since that's time

- not spend on improving health - not spend on improving skills - not spend on improving other projects

Seldom one decides between a side project and starring into the void

Raspberries don't do this by default? The BeagleBoards had this like 15 years ago, I assumed it's standard for all of these SOBs

I don't understand your comparison at all, SDL is a C library not a C++ library

Are you talking about STL? But even there it makes no sense