Header file ostream/istream problems

[Amnesiac]

Trying to compile and link a few files; stuff from Stroustrup's Programming, Principles and Practice regarding the Date class

In the header file I have the following declarations:

ostream& operator<<(ostream& os, const Date& d);
istream& operator>>(istream& is, Date& dd);

and their definitions in the relevant .cpp file.

However, I get the error message (regarding both lines) that says
expected constructor, destructor or type converion before '&' token

What are the culprits?

[kevinkjt2000]

Do you have iostream included?

[Amnesiac]

Yes but it still displays the same error message

[Peter87]

Have Date been declared before these two lines?

[Amnesiac]

Yes, declared with all its member functions and defined in .cpp file

[kevinkjt2000]

I think the culptrit is that iostream is not included in your Date.cpp file, but more information would be needed for me to say otherwise.

I tried doing this to see if it worked:

#include <iostream>

class Date
{
   std::ostream& operator<<(std::ostream& os, const Date& d);
   std::istream& operator>>(std::istream& is, Date& dd);
};

int main()
{
   return 0;
}

g++ gave me this error:

code.cpp:5:60: error: 'std::ostream& Date::operator<<(std::ostream&, const Date&)' must take exactly one argument
code.cpp:6:55: error: 'std::istream& Date::operator>>(std::istream&, Date&)' must take exactly one argument

So I tried this:

#include <iostream>

class Date
{
   std::ostream& operator<<(const Date& d);
   std::istream& operator>>(Date& dd);
};

int main()
{
   return 0;
}

It compiled.

[ne555]

You are using it as a member function

Date today, yesterday = today-1;
today << yesterday; //¿eh? 

std::ostream& operator<<(std::ostream& os, const Date& d); is for a global function (that you may declare as friend of your class)
std::cout << today;

[kevinkjt2000]

Yeah thanks ne555
Maybe Amnesiac will figure out the solution now?
I was just trying to give him something that worked. Could you take a look at the actual question since you fixed mine?

Peter probably has the correct solution though.