Template method inside a class

Question

I have a class called time which has day, month and year.

I have a problem with returning the right value in my method, where it, depending on what we enter as a string "s" it should return an int value from one of those 3 fields.

So, for example, if I want to get days in my date I should call the function d["day"]. My question is, Is there something wrong with my code here? And, what should I put instead of

int operator[] (string s) 
{
    if (s == "day" || s == "month" || s == "year") 
    {
        return ? ? ? ;
    }
}

Answer 1

From the explanation, if I understood correctly, you need the following. You need to return appropriate member (i.e. either day or month or year) according to the string match. (Assuming that you have mDay, mMonth, and mYear as int eger members in your Date class)

int operator[] (std::string const& s) 
{
    if (s == "day")   return mDay;
    if (s == "month") return mMonth;
    if (s == "year")  return mYear;
    // default return
    return -1;
}

or alternatively using a switch statement

// provide a enum for day-month-year
enum class DateType{ day, month, year};

int operator[] (DateType type)
{
    switch (type)
    {
    case DateType::day:   return mDay;
    case DateType::month: return mMonth;
    case DateType::year:  return mYear;
    default:              return -1;
    }
}