Re: C++ Primer ex 7.31

From:
=?ISO-8859-1?Q?Erik_Wikstr=F6m?= <Erik-wikstrom@telia.com>
Newsgroups:
comp.lang.c++
Date:
Fri, 24 Aug 2007 14:12:34 GMT
Message-ID:
<mHBzi.6841$ZA.3561@newsb.telia.net>
On 2007-08-24 15:20, arnuld wrote:

On Fri, 24 Aug 2007 10:59:02 +0000, Erik Wikstr?m wrote:

The problem is that the task is to use add public members, and frankly I
can't see how that is supposed to end up in anything useful.

Using members you could do something like this:

class Foo
{
   int i;
public:
   std::ostream& operator<<(std::ostream& s) {
     return s << i;
   }
   }
   std::istream& operator>>(std::istream& s) {
     return s >> i;
   }
};


one thing i did not get is: why you used "operator>>" rather than ">>" ?


Because that's how you overload the >> operator.

int main()
{
   Foo f;
   f >> std::cin;
   f << std::cout;
}
}
But then it's not "like the input and output operators of standard
library".

 

I would do the exercise with non-member friends instead, since that
would be some useful experience.


you mean no OOP, wrting iostream operators using procedural method ?


Just because it's not a member-function does not make it less OO, IMO.

--
Erik Wikstr?m

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