C++: When should I use structs instead of classes and where are the speed differences?

Question

• When should I use a struct instead of a class? I\'m currently using classes for everything from OpenGL texture wrappers to bitmap fonts.

• Is

Answer 1

as others have explained, they're the same thing except for default access levels.

the only reason why classes can be perceived to be slower is because a good style (but not the only one) is the one mentioned by ArmenTsirunyan: struct for POD types, class for full-fledged object classes. The latter ones usually include inheritance and virtual methods, hence vtables, which are slightly slower to call than straight functions.