Basic Zth usage. This program will print: 
Hello
World!!1
 
#include <cstdio>
 
void world()
{
        printf("World!!1\n");
}
 
void hello()
{
        
        
        
 
        
        
        
        
        printf("Hello\n");
}
 
{
 
        
        
        
        
        
        return 0;
}
int main_fiber(int argc, char **argv)
#define zth_fiber(...)
Prepare every given function to become a fiber by async.
#define async
Run a function as a new fiber.