The issue is, for example, if you have for example a class encapsulating a bunch of flags, and allowing the user to either set each flag seperately, or a bitfield representing all of it.

In C, you might be able to do some magic, but in Java, you’ll need setters and getters there – you can’t even do final fields there.

Luckily, in C#, you can just use accessors, and maybe in Java with Lombok, too.