When to Use Classes vs Structs in C++

In C++, classes and structs are very similar - the only technical difference is that class members are private by default, while struct members are public by default. However, the convention is to use them in slightly different scenarios:

Use structs when you have a simple data type that:

• Mainly consists of public data members
• Has few (if any) member functions
• Doesn't need access control or inheritance

Examples include things like 2D/3D vectors, points, or color values.

Use classes for more complex types that:

• Require access control (public/protected/private)
• Have many member functions
• Use inheritance
• Need to maintain invariants or validate data

Examples include things like a Player class in a game, or a Database class.

So in summary, prefer structs for simple "Plain Old Data" (POD) types, and classes for more complex types that resemble real-world objects with behaviors.