Fix wrapping changes of xmin&xmax methods

wrappers/Python/CoolProp/CoolProp.pyx

@@ -161,10 +161,10 @@ cdef class ChebyshevApproximation1D:
         self.thisptr = new ChebApprox1D(move(expansions_copy))
 
     def xmin(self):
-        return self.thisptr.xmin
+        return self.thisptr.xmin()
     
     def xmax(self):
-        return self.thisptr.xmax
+        return self.thisptr.xmax()
 
     def is_monotonic(self):
         return self.thisptr.is_monotonic()

wrappers/Python/CoolProp/superancillary.pxd

@@ -32,7 +32,8 @@ cdef extern from "superancillary/superancillary.h" namespace "CoolProp::superanc
     cdef cppclass ChebyshevApproximation1D[ArrayType]:
         ChebyshevApproximation1D(vector[ChebyshevExpansion[ArrayType]]&&) except +ValueError
         bool is_monotonic() const
-        const double xmin, xmax
+        double xmin()
+        double xmax()
         void eval_manyC[U](const U x[], U v[], size_t) const
         const vector[ChebyshevExpansion[ArrayType]] m_expansions # The collection of expansions forming the approximation
         const vector[double] m_x_at_extrema # The values of the independent variable at the extrema of the expansions