The C23 edition of Modern C

Important reminder just in the Preface :-)

Takeaway #1: "C and C++ are different: don’t mix them, and don’t mix them up"

Specially relevant to all those folks that insist on "Coding C with a C++ compiler", instead of safer language constructs, and standard library alternatives provided by C++ during the last decades.

Perfectly valid to do if you need to interface with a large C code base and you just want to do some simple OO here and there. Especially if you cannot have runtime exceptions and the like.

This is how I managed to sneak C++ into an embedded C codebase. We even created some templates for data structures that supported static allocation at compile time.

What would be an example of "simple OO here and there" that cannot be done cleanly in plain C?

Namespaces, methods.

Namespaces is not object orientation, is it? Am I missing something? You can place functions (methods) inside of structs in C23, can't you?

On a high level, "object orientation" means you think of your code as representing the state and interactions of objects. You can equally well do this in assembly. If you think of some namespace as a "singleton object" then that's what it is.

I guess what you're really asking is what are the best or most common ways to do OO in C?

Oh. I learned that object orientation is primarily a way to structure data and code, such that the data is encapsulated with the code that works on it, in so called objects. So an Object is the Data, plus the functions that work on the data, an ensure that some invariants are kept. In OO parlance, that code gets executed by sending messages (calling methods).

Where can I find something about objects being "think of your code as representing the state and interactions of objects" honesty totally new to me.

So no, certainly I'm not asking ways to do OO in C. But it seems to be more definitions of object orientation as I thought...