Thread: Overloading

Hi!

I have a class named String which contains member "char *text" and method "void print() const;".

Whenever i declare String class and i want to print that string on the screen i always get the address of the class String (example : 2DEE22).

I just want to do this:

Code:

  ...
  String s("HELLO !!");
  cout << s;

So this must print "HELLO !!" on the screen and not "2DEE22". What I need is that cout << will automatically call print() method.

What do I have to do to correct this problem?

>How is String defined?
Like string except with an upper case S.

>Why are you using a non standard string class when the standard library provides one for you to use?
For fun.

>Did you write a <snip> function?
I would wager not. But for grins, how about defining a

Code:

operator const char *() { return text; }

member function?

>Do you like pie?
I like pie.

>I think most of the people asking questions like the OP did aren't doing it for fun
What a shame, it's quite an experience. Especially if you do it right and try to meet the standard's requirements.

That reminds me, maybe I should update my prestring class to be more l33t. It's been a while since I wrote it.

I already have this method "operator const char *() { return text; }" and it is not working. I still get the address instead of the actual text.

Any other suggestions?


I like pie too .

>and it is not working
You aren't doing something right then. But that's a moot issue anyway because using an implicit conversion overload is fraught with danger (and everyone knows that you can't argue with a statement that uses the word fraught).

>Any other suggestions?
Overload the << operator as Thantos suggested.

How am I supposed to define that friend method in .cpp file?

>How am I supposed to define that friend method in .cpp file?
Your best bet would be to generalize print() for all output streams, then you can do this:

Code:

ostream& String::operator<< ( ostream& out, const String& s )
{
  s.print ( out );
  return out;
}

>Psst Prelude the function should be
Shh! If you don't say anything then maybe nobody will notice.

>And your right there is no way to argue with fraught
My code is fraught with perfection. If it looks wrong then that's only because, in my awesomeness, I anticipated a future addition to the language and started using it. Yea, that's it. I'm so awesome that I can predict the tides of ISO! Hahaha! Make way for my head!

Originally Posted by curlious

My prof is all against friend functions.

Probably he says also that void main is ok....
As far as I know, friend functions are defined by who creates the class, therefore the encapsulation argument, for me, is non-sense.

GaPe, those strange numbers are obviously memory adresses. You need some where to de-reference a pointer.

There is good logic behind that. In general, I tend to avoid friends. If it does need access to the internals of the class, it probably should be a member.

Here is a well articulated rant (particularly against std::string): http://www.gotw.ca/gotw/084.htm