The package named OleCalc don't compile under windows using MSVS19 or Clang both in 64 bits

Contraty to MSVS, clang have 41 compilations error when MSVS have only 1.
Can someone can confirm me OLE/ activeX control can't be compiled using clang but only with MSVS ?

Also, about MSVS : when I try to compile it the first error which is raise is this one :

template <>
inline unsigned GetHashValue(const Guid& guid) { return GetHashValue(~guid); }

Error C912: the explicit specialization 'unsigned int Upp :: GetHashValue (const Upp :: Guid &)' is not a specialization of a function template

If I try to remove the 'template <>' then the next compilation error is :
error C2259: 'Upp :: OcxObjectWrapper <Calculator>': unable to instantiate abstract class

The IViewObject Draw(...) method is abstract

OCX seems to be sort of out of fashion anyway.