How to implement an equality operator function for a proxy class

Question

I have a class Date that I defined that models a date, it has a day,month and a year as data members. Now to compare the dates I created the equality operator

bool Date::operator==(const Date&rhs)
{
    return (rhs.day()==_day && _month==rhs.month() &&_year==rhs.year());
}

Now how do I call the Date class equality operator from the Proxy class...??

This is the edited part of the question

This is the Date Class

//Main Date Class
enum Month 
{
    January = 1, 
    February,
    March, 
    April,
    May,
    June,
    July, 
    August, 
    September,
    October,
    November, 
    December
};
class Date
{
public: 

    //Default Constructor
    Date();
    // return the day of the month
    int day() const
    {return _day;}
    // return the month of the year
    Month month() const
    {return static_cast<Month>(_month);}
    // return the year
    int year() const
    {return _year;}

    bool Date::operator==(const Date&rhs)
    {
    return (rhs.day()==_day && _month==rhs.month() &&_year==rhs.year());
    }

    ~Date();

private:
    int _day;
    int _month;
    int _year;

}

//--END OF DATE main class

This is the proxy class that I will substitute for the Date class

//--Proxy Class for Date Class
class DateProxy
{
public: 

    //Default Constructor
    DateProxy():_datePtr(new Date)
    {}
    // return the day of the month
    int day() const
    {return _datePtr->day();}
    // return the month of the year
    Month month() const
    {return static_cast<Month>(_datePtr->month());}
    // return the year
    int year() const
    {return _datePtr->year();}

    bool DateProxy::operator==(DateProxy&rhs)
    {
        //what do I return here??
    }

    ~DateProxy();

private:
    scoped_ptr<Date> _datePtr;

}

//--End of Proxy Class(for Date Class)

Now the problem that I am having is implementing the equality operator function in the proxy class, I hope this clarifies the question.

Which proxy class? I don't see any in your question ... Anyway, your proxy class surely holds a pointer or reference to the class `Date`, right? So where's the problem in comparing those referenced dates? — celtschk, Nov 13 '11 at 01:01

score 3 · Answer 1 · edited May 23 '17 at 12:03

3

Well, just use the operator:

Date d1, d2;
if(d1 == d2)
    // ...

Notice how the operator== takes a reference. That means, if you have a pointer (or an object acting like a pointer such as scoped_ptr or shared_ptr), then you have to dereference it first:

*_datePtr == *rhs._datePtr;

By the way, you should read this: Operator overloading.

edited May 23 '17 at 12:03

Community

1
1

answered Nov 13 '11 at 00:58

Etienne de Martel

34,692
8
91
111

score 2 · Accepted Answer · answered Nov 13 '11 at 01:32

2

return *_datePtr == *_rhs.datePtr;

answered Nov 13 '11 at 01:32

celtschk

19,311
3
39
64

score 0 · Answer 3 · answered Nov 13 '11 at 00:58

0

It should work like any other equality operator if it is implemented correctly.

Try:

Date a = //date construction;
Data b = //date construction;

if(a == b)
    printf("a and b are equivalent");
else
    printf("a and b are not equivalent");

answered Nov 13 '11 at 00:58

Hunter McMillen

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How to implement an equality operator function for a proxy class

3 Answers3