Extracting Comma seperated data from a .txt file using an object of type istream?

Vehicle Class:

class Vehicle
{
public:
    virtual double topSpeed() const = 0;
    virtual void display(std::ostream&) const = 0;
    virtual std::string condition() const = 0;
    virtual ~Vehicle() {};
};    

Car Class:

class Car : public Vehicle
{
    std::string m_maker;
    std::string m_condition;
    int m_topSpeed;

public:
    Car(std::istream&);
    std::string condition() const;
    double topSpeed() const;
    void display(std::ostream& out) const;

};

I need to use the Car(std::istream&) function to extract comma seperated data from a .txt file using STL containers and iterators.

.txt file below:

c, Toyota  , n, 157
c, Honda   , b, 145
c, Chrysler, n, 173

Using that function above, i need to get each value seperately in the following format:

TAG | MAKER | CONDITION | TOP_SPEED |

tag is the "c", maker is the "car name", condition is the "n/b" and speeds are the int values.