#define _PDCLIB_cc( x, y ) x ## y
#define _PDCLIB_concat( x, y ) _PDCLIB_cc( x, y )
+#define _PDCLIB_concat3( x, y, z ) _PDCLIB_concat( _PDCLIB_concat( x, y ), z )
#define _PDCLIB_symbol2value( x ) #x
#define _PDCLIB_symbol2string( x ) _PDCLIB_symbol2value( x )