Creating a Mimic Class

[Sh0es]

I have two classes that are functionally identical, but which I want to make separate so that the same class of object can be used in different constructors for another class. I decided to make my second class inherit from the first.

Here's my code.

#ifndef INFOREADER_H
#define INFOREADER_H

#include <iostream>
#include "ArrayList.h"

using namespace std;

class TextReader //interface for reading the passwd or group file
{
public:
    ArrayList<char> getText() //reads from a file
    {
        ArrayList<char> output = ArrayList<char>(256);

        for(int i = 0; i < 256; i++)
            output.append('\0');
		
        while(!(in.eof()))
            in.get();

        int i = 0;

        while(in.get() != '\0')
        {
            output.insert(in.get(), i);
            in.get();
            ++i;
        }

        return output;
    }

    ArrayList<ArrayList<char> > parseText(ArrayList<char> block) //formats info from file
    {
        ArrayList<char> temp = ArrayList<char>();
        ArrayList<ArrayList<char> > turn = ArrayList<ArrayList<char> >();
		
        for(int i = 0; i < block.getSize(); i++)
        {
            if(block[i] == '\n')
                ++i;
            else
            {
                while(block[i] != '\n')
                    temp.append(block[i]);

                turn.append(temp);
                temp = ArrayList<char>();
            }
        }

        return turn;
    }
    TextReader(istream& i): in(i)
    {}
    virtual ~TextReader()
    {}

protected:
    istream& in;
};

class InputReader: public TextReader //for reading P1Input
{
public:
    InputReader(istream& i): in(i) //I'd make 'i' const but that annoyed the compiler
    {} //apparently, 'in' is not a member, so it didn't get initialized
    virtual ~InputReader()
    {}
};

The second class' constructor is giving me a "No default constructor" error when I compile even though it's exactly like the first one.

I tried assigning in inside the brackets, but that didn't work since the istream's operator= is private.

Any insight available?

[ne555]

http://en.cppreference.com/w/cpp/language/initializer_list (initialization order)
To construct the derived class you need to construct the base class first. However, you do not have any call to a base class constructor in your initialization list.
The compiler guess that you want to use the default constructor for the base class, but in your case you do not have a default constructor, so it fails.

InputReader(std::istream &i): TextReader(i)
{}

> so that the same class of object can be used in different constructors for another class.
¿care to expand?

[Sh0es]

The classes function the same way but they're intended for different types of files. One is for save files while the other is for a sequence of scripts. Don't ask why I'm not using <fstream>.