Passing ostream object to an constructor of unmanaged class...

[svkr2k]

Dear forum members,

I have an unmanaged dll written in C++ using Visual Studio 6.0. I need to use this dll in an VC++ .Net application. The unmanaged dll has a class called CUnmanaged. Its constructor accepts reference to ostream object:

CUnmanaged::CUnmanaged( ostream& os )
{
/* ... */
}

In the VC++.Net client application, the object of CUnmanaged is created as follows:

filebuf fb;
fb.open ("c:\\test1.txt",ios:: out);
ostream os(&fb);
os << "Test sentence\n";
CUnmanaged objUnmanmaged( os );
fb.close();

When linking, I get the following error:
error LNK2001: unresolved external symbol "public: __thiscall CUnmanaged::CUnmanaged(class std::basic_ostream<char,struct std::char_traits<char> > &)" (??CUnmanaged@@$$FQAE@AAV?$basic_ostream@DU?$char_traits@D@std@@@std@@@Z)

Can anyone suggest some solution for this ?
Thanks in advance.
-Rajesh.

[Andreas Masur]

Make sure that you have added all needed files for the dll (header plus import library). Other than that....did you export the constructor from the dll?

[svkr2k]

Hi Andreas Masur,

The class CUnmanaged is declared as:
class __declspec (dllexport) CUnmanaged
{
public:
CUnmanaged( ostream& os );

CUnmanaged( const std::string& filename );

/* more methods */

}

So, I hope the constructors are exported ?