#define macro_to_func(pp) ({printf("in Macro ...\n"); minus ;})
void do_something(int *a, int *b){
printf("do_something\n");
printf("do_something %d \n", c);
int minus(int *a, int *b){
printf("minus a = %d \n", *a);
printf("minus b = %d \n", *b);
printf("minus %d \n", c);
int (*do_something)(int* c, int* d);
//printf("fptr 1 do_something %p\n", &do_something);
printf("do_something = macro_to_func\n");
do_something = macro_to_func(pp);
//printf("fptr minus %p\n", &minus);
//printf("fptr 2 do_something %p\n", &do_something);
do_something(&m, &n); --------------------------->???