Question

在 ...\MxDraw52\Src\MxDraw5.2\ArxInc\Mdsdef.h中，我们看到了链表的如下定义：

#ifndef _mdsdef_h
#define _mdsdef_h 1
 
 
#define TRUE    1
#define FALSE   0
#define EOS     '\0'
 
#pragma pack(push, 8)
 
typedef double   mds_real;
typedef mds_real mds_point[3];
typedef long     mds_name[2];
typedef mds_real mds_matrix[4][4];
 
 
typedef mds_real *mds_pointp;
typedef long     *mds_namep;
 
 
 
#ifdef X
#undef X
#endif
#ifdef Y
#undef Y
#endif
#ifdef Z
#undef Z
#endif
#ifdef T
#undef T
#endif
 
#ifndef _XYZT_DEFINED
#define _XYZT_DEFINED
enum { X = 0, Y = 1, Z = 2 }; 
enum { T = 3 };              
#endif 
 
 
#define PAUSE "\\"
 
 
enum {
    RSG_NONULL      = 0x01,  
    RSG_NOZERO      = 0x02,  
    RSG_NONEG       = 0x04,  
    RSG_NOLIM       = 0x08,  
    RSG_GETZ        = 0x10,  
    RSG_DASH        = 0x20,  
                             
    RSG_2D          = 0x40,  
                             
    RSG_OTHER       = 0x80,  
    RSG_DDISTFIRST  = 0x100,
 
RSG_NOXORDRAG   = 0x200,
 
 
RSG_DYNXYCOORDINPUT = 0x400,
REG_DYNANGELINPUT   = 0x800,
REG_DISTANCEINPUT = 0x1000,
RET_AUTOINPUT       = 0x2000
};
 
 
enum {
    INP_NNULL   = RSG_NONULL,
    INP_NZERO   = RSG_NOZERO,
    INP_NNEG    = RSG_NONEG,
    INP_NLIM    = RSG_NOLIM,
    INP_DASH    = RSG_DASH,
    INP_NZCOORD = RSG_2D
};
 
 
struct mds_binary {    
    short clen;        
    char *buf;        
};
 
 
union mds_u_val {
   mds_real rreal;
   mds_real rpoint[3];
   short rint;
   LPTSTR rstring;
   long rlname[2];
   long rlong;   
   struct mds_binary rbinary;
   unsigned char ihandle[8];
/*#ifdef _WIN64*/
__int64 objId;
// #else
//    long objId;
// #endif
   void*  pObj;
}; 
 
 
struct resbuf {                                                  
        struct resbuf *rbnext; 
        short restype;
        union mds_u_val resval;
resbuf()
{
restype = 5003 ; // RTSHORT
rbnext  = 0;
resval.rint = 0;
}
};
 
typedef struct resbuf *pResbuf;
typedef const struct resbuf *kpResbuf;
 
#pragma pack(pop)
 
#endif