CODEWITHSUNDEEP
c++fileoperator-overloading
Andy
Andy

Reputation: 155

Overloading the extraction operator

I'm overloading the extraction operator to read a node which contains a pair of numbers.

As you can see I'm printing a message for the user to know which number they are writing. However when I read from a file the messages will still print. So I want to know if there is a way to check if I'm reading from a file or from the keyboard or if there is another way to avoid printing the messages when I'm reading from a file.

Code:

istream &operator>>( istream &input, nod &X )
{
    cout<<"Number 1: ";
    input>>X.info1;
    cout<<"Number 2 ";
    input>>X.info2;
    X.next=NULL;
    return input;
}

Upvotes: 1

Views: 167

Answers (1)

molbdnilo
molbdnilo

Reputation: 66401

You shouldn't interact with a user at all in the streaming operators.
That's not what they're for, and operator>> should just read the next object that's in the stream.

Instead, interact first and then construct the object:

nod read_nod()
{
    int info1 = 0;
    cout << "Number 1: ";
    cin >> info1;
    int info2 = 0;
    cout << "Number 2: ";
    cin >> info2;
    return nod(info1, info2); 
}

or

istream & operator>> (istream &input, nod &X)
{
    input >> X.info1;
    input >> X.info2;
    X.next = NULL;
    return input;
}

nod read_nod()
{
    cout << "Enter two numbers for the nod: ";
    nod n;
    cin >> n;
    return n;
}

Upvotes: 2

Related Questions