>>83
#ifdef __cplusplus
#define _static
#define _extstatic extern
namespace {
#else
#define _static static
#define _extstatic static
#endif

_extstatic struct A a[];
_static struct A b[] = {{"1st in b[]", a}, {"2nd in b[]", a+1}};
_static struct A a[] = {{"1st in a[]", b}, {"2nd in a[]", b+1}};

#ifdef __cplusplus
}
#endif

まぁ、確かにこんだけ書けばCでもC++でも無警告でコンパイル通ったけど、
まぁ面倒ですこと(ﾟдﾟ)！