Why can’t you treat a FILETIME as an __int64?

The FILETIME structure represents a 64-bit value in two parts: typedef struct _FILETIME { DWORD dwLowDateTime; DWORD dwHighDateTime; } FILETIME, *PFILETIME; You may be tempted to take the entire FILETIME structure and access it directly as if it were an __int64. After all, its memory layout exactly matches that of a 64-bit (little-endian)...