Unable to Construct ifstream Object

[Sh0es]

I'm trying to declare an ifstream intended to be opened upon a function call (I enter a filename into the program and then the ifstream opens), but every time I get a "use of deleted function" error. Could someone explain or help?

[pearlyman]

Can you post your code so we can see what's going on please?

[Sh0es]

int main()
{
    ArrayList<string>* filter;
    ArrayList<Star> starDB = ArrayList<Star>();
    ArrayList<Planet> pdb = ArrayList<Planet>();

    string filename = string();
    ifstream inf; //ifstream in question
    char inp;
    float inum = -1.0;
    char sortedBy = '0';

    cout << "Welcome to ExoPlanIt. Please enter the name of a planetary system file to upload it." << endl;
    cin >> filename;

    starDB.append(addSystem(filename, inf, filter));
    pdb += starDB[starDB.getSize() - 1].getPlanets();

    while(true)
    {
    
        /.../

        else if(inp == 'A')
        {
	    try
	    {
	        cin >> skipws >> filename;
		starDB.append(addSystem(filename, inf, filter)); //addSystem is the function that opens the isftream
	        pdb += starDB[starDB.getSize() - 1].getPlanets();
		cin >> skipws >> inp;
	    }
	    catch(ios_base::failure& ff)
	    {
	        cout << "Error: File could not be opened." << endl;
	    }
        }

        /.../
    }
}

I should mention that I get a similar error (same type, different details) when I try to instantiate the ifstream in main with a default constructor (ifstream()).

[JLBorges]

Pass the stream by reference (streams are not CopyConstructible).

//... addSystem(  ... , std::ifstream, .... ) ;
... addSystem(  ... , std::ifstream&, .... ) ;

[Sh0es]

But... I do pass it by reference.

The code that's causing an error specifically is

inp = ifstream(name, ios_base::in);

Where inp is an ifstream& passed from the function call.

[JLBorges]

That should work with a conforming implementation of the standard library; though a file stream is not CopyAssignable, it is MoveAssignable

Use this construct to open the file; it should work everywhere: inp.open( name, std::ios_base::in ) ;