How to convert an object to a string?

[Ey80oG1T]

So let's say that we have a class called Date for example. And you want to convert an object of a date to a string, so you can do this:

Date holiday;

std::cout << holiday;

Here's my code inside the Date class:

operator string () // converts objects into strings
{
    dateInString += to_string(month) + " / ";
    dateInString += to_string(day) + " / ";
    dateInString += to_string(year) + " / ";

    return dateInString;
}

But this isn't working. How do I fix this?

[dutch]

You need to say

std::cout << std::string(holiday);

Or overload operator<<, too:

#include <iostream>
#include <string>

struct Date
{
    int year, month, day;

    Date(int y, int m, int d) : year{y}, month{m}, day{d} {}

    operator std::string() const
    {
        return std::to_string(month) + " / "
             + std::to_string(day)   + " / "
             + std::to_string(year);
    }
};

std::ostream& operator<<(std::ostream& out, const Date& d)
{
    return out << std::string(d);
}

int main()
{
    Date holiday(1997, 2, 13);
    
    // Not using operator<< overload
    std::cout << std::string(holiday) << '\n';

    // Using operator<< overload
    std::cout << holiday << '\n';
}

[Repeater]

But this isn't working. How do I fix this?

In your particular code example, you seem to be trying to use the variable dateInString without creating it. You can't use variables that don't exist.