c++ 0verloading operators

Question

0.00/5 (No votes)

See more:

Hi,

I was looking over some online tutorials/examples on operator overloading. They where very informative but I was looking for something a little different.

The tutorials had:

#include<iostream.h>
#include<fstream.h>

class ThreeD
{
  int x,y,z;
public:
  ThreeD(int i,int j,int k){
    x=i;
    y=j;
    z=k;
  }
  
  friend istream& operator>>(istream& stream,ThreeD ob);
};


istream& operator>>(istream& stream,ThreeD  ob)
{
  stream>>ob.x>>ob.y>>ob.z;
  return stream;
}
main()
{
  
  ifstream in("test");
  
  ThreeD o3(0,0,0),o4(0,0,0);
  in>>o3>>o4;
  return 0;
}

but I was wondering if you could do something more like:

ThreeD o3;

o3 >> 0 >> 20 >> 6;

I know STL has a class for this. I want to know if it can be done this way

Posted 12-Jul-11 13:37pm

me3344

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

TRK3 · Accepted Answer · 2011-07-12T14:23:00

ThreeD o3;

o3 >> 0 >> 20 >> 6;

Would mean you defined an operator something like:

ThreeD& operator>> (ThreeD &obj, int x)
{
    // What do you want to do here???

    return obj
}

Do you actually mean:

ThreeD o3;

o3 << 0 << 20 << 6;

In which case you'd define something like:

class ThreeD
{
  int x,y,z;

  int last;
public:
  ThreeD() { 
    x = y = z = 0;
    last = 0;
  }

  ThreeD(int i,int j,int k){
    x=i;
    y=j;
    z=k;
    last = 3;
  }
  
  friend ThreeD& operator>>(ThreeD& obj,int i);
};
 
ThreeD& operator>>(ThreeD& obj, int i)
{
    switch (obj->last) {
       case 0:   obj->x = i;  break;
       case 1:   obj->y = i;  break;
       case 2:   obj->z = i;  break;
       default:
          throw "Already got three numbers can't input any more!";
    }
    obj->last++;
 
    return obj;
}