cannot convert from int & missing default paramete

I am developing new project in Qt with existing MFC project . SO in MFC I have a function which uses SYSTEMTime and return CString.

example

    CString getTimestampString( void )
{
    SYSTEMTIME      systemTime;
    CString         datestr;

    GetSystemTime( &systemTime );

    datestr.Format( "%02i/%02i/%04i, %02i:%02i:%02i",
        systemTime.wDay, systemTime.wMonth, systemTime.wYear,
        systemTime.wHour, systemTime.wMinute, systemTime.wSecond );

    return ( datestr + "; " + get_file_version_info().ProductName.c_str() + ", " + get_file_version_info().ProductVersion.c_str() );
        // get_file_version_info  are in some other director under lib_know directory.
}

The above function compile in VS2010.

Now doing same thing in QT

   QString getTimestampString( void )
{
   QDateTime        systemTime = QDateTime::currentDateTime();
      QString            datestr    = systemTime.toString() ;

   return( QString("%1; %2, %3").arg( datestr )
                                .arg( get_file_version_info().ProductName.c_str() )
                                .arg( get_file_version_info().ProductVersion.c_str() ) 
                                 ) ;

  }

I got following errors

  C:\mydir\application\libs\lib_know/FileVersioninfo.h(83): error C2440: 'default argument' : cannot convert from 'int' to 'know::FileVersionInfo::Pcalculator'
1>

Source or target has incomplete type

1>C:\mydir\application\libs\lib_know/FileVersioninfo.h(83): error C2548: 'know::init_file_version_info' : missing default parameter for parameter 1

PS -> I cant able to make any changes in lib_know as this library is being used by many other projects..

Please let me know where I am falling , I am completely clueless now.

Thanks and regards,

SOLVED !!!!!.. the know::init_file_version_info was using some boost library which I have not included by using hit and trail method It works now... The interesting thing was that compiler was not throwing any linker error or anything related to boost functions