#define %alias %feature("alias")
#define %freefunc %feature("freefunc")
#define %markfunc %feature("markfunc")
#define %mixin %feature("mixin")
#define %predicate %feature("predicate", "1")
#define %bang %feature("bang", "1")
#define %trackobjects %feature("trackobjects")
#define %nooutput %feature("outputs","0")
#define %initstack %feature("initstack", "1")
#define %ignorestack %feature("initstack", "0")