How to write a function pointer to a function returning a function pointer to a function?

Question

I want to assign a function\'s address to a function pointer, but the function to be addressed returns a function pointer with the same signature as itself, causing it to recurs

Answer 1

The trick in C is to take advantage of the fact that any kind of function pointer can be cast to any other kind of function pointer:

#include 
#include 

typedef void(*emptyfunc)(void);
typedef emptyfunc (*funcptr2)(int);

funcptr2 strategy(int m)
{
  printf("Strategy %d.\n", m);
  return (funcptr2)&strategy;
}

int main (void)
{
  const funcptr2 strategy2 = (funcptr2)strategy(1);
  const funcptr2 strategy3 = (funcptr2)strategy2(2);
  strategy3(3);

  return EXIT_SUCCESS;
}

Each pointer to a strategy is always in a type that can be called once, and the return value is put back into a form that can be called once again.

In C++, you would declare a function object:

class strategy {
  public:
  virtual const strategy& operator()(int) const = 0;
}

An instance of this class can be called like a function.