Thread: Open file?

I am trying to open a file using the following code,

Code:

ifstream a_file ( "D:\\ LotteryProgram / MegaMill" );
   //Opens MegaMill for reading the file
  
            if ( !a_file.is_open() )
                 {
                    cout << " The file could not be opened" << endl;
                    (a_file.open());
                 }

            else {
                    cout << "Safely use the file stream" << endl;
                    cin.get();
                 }

but I am getting an error:

"Error 1 error C2661: 'std::basic_ifstream<_Elem,_Traits>:pen' : no overloaded function takes 0 arguments"

and I don't understand it. Why do I get an error when I tell the program to open a_file if it is not open? Can someone translate this error into English so I can make sense of it? ....therry