#include <TColStd_Array1OfReal.hxx>
#include <Standard_Real.hxx>
#include <GccEnt_Position.hxx>
-class Standard_NegativeValue;
-class Standard_OutOfRange;
-class GccEnt_BadQualifier;
-class StdFail_NotDone;
class Geom2dGcc_QCurve;
class gp_Lin2d;
class gp_Circ2d;