When you should:
- When your project coding guidelines say you should
When you shouldn't:
- When your project coding guidelines say you shouldn't
If you don't have any guidelines yet, you're free to choose whatever you or your team want and feel most comfortable with. Personally when coding C++ I tend to use m_ for members, it does help. When coding in other languages, particularly those without true classes (like Javascript, Lua) I don't.
In short I don't believe there is a "right" and a "wrong" way.
