> That's why you can even find C++ libraries use this idiom even though C++ obviously has `private`. It's about having a stable, opaque API. In C++ this is a p

> That's why you can even find C++ libraries use this idiom even though C++ obviously has `private`. It's about having a stable, opaque API. In C++ this is a popular idiom and a standard technique covered by multiple references under the name pointer to implementation (pimpl). This is not a C thing beyond the point that C has pointers.