#define __getFieldPtr__(obj, field)        (&((obj)->field))
        #define __getField__(ptr, offset, type)    (* (*type) ( __addrFromPtr__(ptr) + offset ) )
        #define __alignOf__(type)                  (offsetof(struct { char c; type member; }, member))
        #define __fieldParentPtr__(type, field, instance)  ((type *)(__addrFromPtr__(instance) - offsetof(type, field)))
        #define __arrayLen__(array)                (sizeof(array) / sizeof(array[0]))
    // text
        #define __CTextLen__(str)                  (__arrayLen__(str) - 1)

        #define __CTextPtr_fromCText__(text)       ((char(*)[__CTextLen__(text)]) text)
        #define __CTextPtr_lvalue__(name, text)    (char(*name)[__CTextLen__(text)])
        #define __CTextPtr_declare__(name, text)   __CTextPtr_lvalue__(name, text) = __CTextPtr_fromCText__(text)
        
        // slice
            #define __len_and_text__(str)              __CTextLen__(str), str
            #define __text_and_len__(str)              str, __CTextLen__(str)
            #define __Slice_fromCText__(text)          {.ptr=text, .len=__CTextLen__(text)}
    // crypto
        #define Sha1_block_size 64
        #define Sha1_digest_length 20
    // Network
        
        #define max_allowed_listen_port 49151
        #define PRISOCK "%llx"