Re: How to use operator overloading?

From:
"io_x" <a@b.c.invalid>
Newsgroups:
comp.lang.c++
Date:
Mon, 18 Jan 2010 11:47:04 +0100
Message-ID:
<4b543a43$0$1114$4fafbaef@reader2.news.tin.it>
"osmium" <r124c4u102@comcast.net> ha scritto nel messaggio
news:7rh57oFoa8U1@mid.individual.net...

#include <iostream>
using namespace std;

class INT
  {
  public:
    INT() {}
    INT(int a) { datum = a;}
    void show() {cout << "INT datum: " << datum << endl;}
    INT operator+(INT rhs) { return datum + rhs.datum;}
  private:
    int datum;
  };

int main()
  {
  INT a(7), b(5), c;
  a.show();
  b.show();
  c = a + b; // default operator= is perfectly
                  // adequate for a shallow copy situation like this
  c.show();
  cin.get(); // crutch for my compiler
  }

Get the fundamentals straight, THEN you can worry about const correctness,
reference vs. value, etc.


what about this?

#include <iostream>
using namespace std;

class intc{
public:
 int datum;
 intc() {}
 intc(int a){datum=a;}
 void show() {cout << "intc datum: " << datum << endl;}
 intc operator+(intc rhs) {return datum+rhs.datum;}
 intc& operator-(intc& rhs);
 friend ostream& operator<<(ostream& ost, intc& b)
 {ost << b.datum << flush; return ost;}
};

unsigned index=0;
intc v[16];

intc& intc::operator-(intc& rhs)
{unsigned u;
 v[u].datum=datum-rhs.datum;
 ++index; if(index==16) index=0;
 return v[u];
}

int main(void)
{intc a(7), b(5), c, n(3);
 cout << a << "+" << b << "-" << n << "=";
 c=a+b-n; // default operator= is perfectly
           // adequate for a shallow copy situation like this
 cout << c << "\n";
 cin.get(); // crutch for my compiler
 return 0;
}

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