_Bool

  Typ: _Bool
  1 Byte
  0 and 1

  ( the underscore '_' and Shift B is nessesary )

#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */
 
 
int main(void)
{
   printf("_Bool: %d bytes\n", sizeof(_Bool) );
 
   return 0;
}