#include <Standard_Real.hxx>
#include <Standard_Boolean.hxx>
#include <Standard_Integer.hxx>
-class Standard_ConstructionError;
-class Standard_RangeError;
-class Geom_UndefinedDerivative;
class Geom_Curve;
class gp_Ax1;
class gp_Dir;
-class gp_Pnt;
class gp_Ax2;
class gp_Trsf;
class gp_GTrsf2d;