Playing around with the idea of Maybe/Option/Optional type in C using silly macros

optional.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#define maybe(type) maybe_##type
#define some(type, v) ((maybe(type)) { .is_something = 1, .value = v})
#define nothing(type) ((maybe(type)) { .is_something = 0 })
#define unwrap(x) (is_nothing(x) ? abort() : 0, x.value)
#define is_nothing(x) (x.is_something == 0)
#define ifsome(x) if (!is_nothing(x)) 
#define maybe_set(x,v) (x.value=v)

#define make_maybe_type(type) \
typedef struct\
{\
  u8 is_something;\
  type value;\
} maybe(type);


typedef int* intptr;
typedef uint8_t u8;
typedef void* voidptr;

make_maybe_type(int);
make_maybe_type(intptr);
make_maybe_type(voidptr);

maybe(voidptr) alloc(size_t size) {
  void *mem = malloc(size);

  if (!mem) {
    return nothing(voidptr);
  }

  return some(voidptr, mem);
}

typedef struct
{
  maybe(int) initial_x;
  maybe(int) initial_y;
} Config;

int main(void) {

  maybe(int) x = some(int, 10);
  maybe(intptr) z = some(intptr, &x.value);

  if (is_nothing(x)) {
    printf("Nothing!\n");
  } else {
    printf("Value = %d\n", x.value);
  }

  Config c = { 0 };

  int xpos = is_nothing(c.initial_x) ? 100 : c.initial_x.value;
  int ypos = is_nothing(c.initial_y) ? 100 : c.initial_y.value;

  printf("(%d, %d)\n", xpos, ypos);

  int *values = unwrap(alloc(100));

  x = some(int, 234);
  ifsome(x) {
    printf("Value = %d\n", x.value);
  }
  return 0;
}

Could be useful for configuration/options and small programs/tools...