Can I define a function inside a C structure? [duplicate]

Answer 1

In C it is not allowed to define a method inside a struct. You could define a function pointer inside a struct as follows:

typedef struct  {
  double x, y, z;
  struct Point *next;
  struct Point *prev;
  void (*act)();
} Point;

You will have to assign the pointer to a specific function whenever you instantiate the struct.