>>461
-----t0.h
#ifndef t0_h
#define t0_h
#include "t1.h"
struct a {
struct b *b;
};
typedef struct a a;
#endif
-----t1.h
#ifndef t1_h
#define t1_h
#include "t0.h"
struct b {
struct a *a;
};
typedef struct b b;
#endif