typedef enum _cairo_format {
    CAIRO_FORMAT_ARGB32,
    CAIRO_FORMAT_RGB24,
    CAIRO_FORMAT_A8,
    CAIRO_FORMAT_A1
    /* The value of 4 is reserved by a deprecated enum value.
     * The next format added must have an explicit value of 5.
    CAIRO_FORMAT_RGB16_565 = 4,
    */
} cairo_format_t;

#define CAIRO_FORMAT_INVALID ((unsigned int) -1)
#define CAIRO_FORMAT_VALID(format) ((format) <= CAIRO_FORMAT_A1)

#include <stdio.h>
int main()
{
  cairo_format_t format = CAIRO_FORMAT_INVALID;
  printf("valid? %d\n", CAIRO_FORMAT_VALID(format));
}