#include <stdio.h>
#include <string.h>

int is_negative(double n)
{
  // Not a good idea: long x = *(long *)&n;
  long x;
  memcpy(&x, &n, sizeof(long));
  return (x >> 63) & 1;
}

int main()
{
  printf("%d\n", is_negative(10.0));
  printf("%d\n", is_negative(-10.0));
  return 0;
}