Cmass

#include <iostream>
#include <string>
#include <sstream>


using namespace std;

class Cmass {

    private:                 //make it private when finished
        float mass;
        string index;

    public:
        Cmass()          //konstruktor domyslny; masa 0.0 index: kg
        {
            mass = 0.0;
            index = "kg";
        }
        Cmass(const string &new_mass_const)  //konstruktor przyjmuje string i ustawua mass i index w zaleznosci od tego co w stringu
        {
            string new_mass = new_mass_const;
            int i = new_mass.length();
            if (new_mass.at(i-1) == 't')
                {
                    new_mass.erase(i);
                    istringstream iss(new_mass);
                    iss >> mass;
                    index = "t";
                }
            else
                {
            if (new_mass.at(i-1) == 'g')
                {
                    if(new_mass.at(i-2) == 'k')
                    {
                    new_mass.erase(i);
                    new_mass.erase(i-1);
                    istringstream iss(new_mass);
                    iss >> mass;
                    index = "kg";
                    }
                    else
                {
                    new_mass.erase(i-1);
                    istringstream iss(new_mass);
                    iss >> mass;
                    index = "g";
                }
                }
            else
                {
                    istringstream iss(new_mass);
                    iss >> mass;
                    index = "kg";
                }

                }
        }
        Cmass(float new_mass = 0.0)
        {
            mass = new_mass;
            index = "kg";
        }

        float conv2kg(Cmass obj);
        float conv2kg(Cmass* pobj);

 //PRZECIAZANE OPERATORY

        operator float()
        {
             return mass;
        }
        operator string();
        bool operator < (const Cmass & first);
        bool operator + (Cmass &second);
        friend bool operator - (const Cmass &second);
        friend ostream &operator << (ostream &output, const Cmass &mass);

};

ostream &operator << (ostream &output, const Cmass &mass)
    {
       return output <<mass.mass <<mass.index<<endl;
    }


bool Cmass::operator + (Cmass &second)
            {

            this->mass = conv2kg(this) + conv2kg(second);
                if (this->mass < 1)
                    {
                        this->mass = this->mass / 0.001;
                        this->index = "g";
                        return true;
                    }
                if  (this->mass > 1000)
                    {
                        this->mass = this->mass / 1000;
                        this->index = "t";
                        return true;
                    }

            this->index = "kg";
            return true;
        }

float Cmass::conv2kg(Cmass obj)
        {
            float obj_mass = obj.mass;
                if(obj.index == "g")
                    {
                        obj_mass = obj_mass * 0.001;
                        return obj_mass;
                    }
                if (obj.index == "kg")
                    {
                        return obj_mass;
                    }
                if (obj.index == "t")
                    {
                        obj_mass = obj_mass * 1000;
                        return obj_mass;
                    }
                return 0;
        }

float Cmass::conv2kg(Cmass* pobj)
        {
            Cmass obj = *pobj;
                if(obj.index == "g")
                    {
                        obj.mass = obj.mass * 0.001;
                        return obj.mass;
                    }
                if (obj.index == "kg")
                    {
                        return obj.mass;
                    }
                if (obj.index == "t")
                    {
                        obj.mass = obj.mass * 1000;
                        return obj.mass;
                    }
                return 0;
        }

int main()
{
    Cmass obj1(string("120kg"));
    Cmass obj2(string("2t"));
    Cmass obj3(string("0kg"));
    obj3 = obj1 + obj2;
    cout<< obj1;
    cin.get();
    return 0;
}