Function is_big_endian

extlibs/fmt/include/fmt/format.h:249–255

}

inline bool is_big_endian() {
  const auto u = 1u;
  struct bytes {
    char data[sizeof(u)];
  };
  return bit_cast<bytes>(u).data[0] == 0;
}

// A fallback implementation of uintptr_t for systems that lack it.
struct fallback_uintptr {