Hiding members in a C struct

Question

I\'ve been reading about OOP in C but I never liked how you can\'t have private data members like you can in C++. But then it came to my mind that you could create 2 structu

Answer 1

My solution would be to provide only the prototype of the internal struct and then declare the definition in the .c file. Very useful to show C interface and use C++ behind.

.h :

struct internal;

struct foo {
   int public_field;
   struct internal *_internal;
};

.c :

struct internal {
    int private_field; // could be a C++ class
};

Note: In that case, the variable have to be a pointer because the compiler is unable to know the size of the internal struct.