#pragma once
/* Portable be64toh() — big-endian to host byte order conversion. */
#if defined(__linux__)
#  ifndef _DEFAULT_SOURCE
#    define _DEFAULT_SOURCE 1
#  endif
#  ifndef _BSD_SOURCE
#    define _BSD_SOURCE 1
#  endif
#  include <endian.h>
#  ifndef be64toh
   /* musl and some older glibc: fall back to builtin */
#  include <stdint.h>
static inline uint64_t be64toh(uint64_t x) {
#    if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
    return __builtin_bswap64(x);
#    else
    return x;
#    endif
}
#  endif /* be64toh */
#elif defined(__APPLE__)
#  include <machine/endian.h>
#  include <libkern/OSByteOrder.h>
#  define be64toh(x) OSSwapBigToHostInt64(x)
#else
#  include <stdint.h>
static inline uint64_t be64toh(uint64_t x) {
#  if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
    return __builtin_bswap64(x);
#  else
    return x;
#  endif
}
#endif