*  the first entry in the structure is a magic number.
 */
#ifdef NO_BOMBING_MACROS
#  define BU_CKMAG(_ptr, _magic, _str)
#  define BU_CKMAG_TCL(_interp, _ptr, _magic, _str)
#else
#  define BU_CKMAG(_ptr, _magic, _str)  \
        if( !(_ptr) || ( ((long)(_ptr)) & (sizeof(long)-1) ) || \
            *((unsigned long *)(_ptr)) != (unsigned long)(_magic) )  /*{*/ \
                bu_badmagic( (long *)(_ptr), (unsigned long)_magic, _str, __FILE
        }
#  define BU_CKMAG_TCL(_interp, _ptr, _magic, _str)     \
        if( !(_ptr) || ( ((long)(_ptr)) & (sizeof(long)-1) ) || \
             *((long *)(_ptr)) != (_magic) ) /* { */\
                bu_badmagic_tcl( (_interp), (long *)(_ptr), (unsigned long)_magi
                return TCL_ERROR; \
        }
#endif