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C opaque pointers

In C an opaque pointers allow to use a struct, while hidding its implementation and field.

Usage

// car.h
typedef struct myCar Car;

Car *createCar();
void addWheels(Car *c);

// car.c
typedef struct myCar {
    int nbrWheels;
    char *color;
} Car;

A file that include ‘car.h’, will be able to create and use the Car struct, without accessing the color and nbrWheels attributes.

!! the user’s of Car can only use pointer to it, and cannot dereference it.