I don't mind it for thing like pyplot where you have tons of style options hidden away like that. But I'd definitely like to be able to say this one isn't opti

I don't mind it for thing like pyplot where you have tons of style options hidden away like that. But I'd definitely like to be able to say this one isn't optional or implicitly default constructed (or worse uninitialized, maybe that is already precluded by any amount of brace initialization, or maybe not if the class is POD, I'll have to check). Someone suggested below deleting default constructors, you could make a template class that did that and forwarded other constructors, but I'd still like to be able to allow explicit default initialization in the ones that aren't considered optional.