Trying to overload the << operator using C++

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3 total messages Started by Jim Tue, 08 Jun 2004 11:52

#2389

Author: Jim
Date: Tue, 08 Jun 2004 11:52

34 lines
1274 bytes

I am trying to overload the << operator to a bag that is a class. 
container is a bag.

class bag;





bags_to_use = 12;

bag container[bags_to_use];  // A declared bag of arrays.



So you have a structure that is an array initialized of 12 containers.

I would think that the correct implementation of overloading the 
operator would be something of the following:

ostream& operator <<(ostream& outs, const bag& container[bags_to_use])
{

stuff I will write later.

}

but I think that I may be wrong?  Is my syntax wrong?



thanks,

Jim

Re: Trying to overload the << operator using C++

#2390

Author: Aquila
Date: Wed, 09 Jun 2004 05:32

23 lines
1795 bytes

Jim wrote:

> bag container[bags_to_use];��//�A�declared�bag�of�arrays.
> 
> 
> 

you don't want to write an output operator for just this array right?

> ostream& operator <<(ostream& outs, const bag& container[bags_to_use])
> {
> 
> stuff I will write later.
> 
> }
> 
> but I think that I may be wrong?��Is�my�syntax�wrong?
> 
I don't think it's possible to have a variable array size in a definition...
if it does work: did you put this operator in your class? what errors do you
get?
-- 
"May the source be with you"

Re: Trying to overload the << operator using C++

#2392

Author: Matata
Date: Wed, 09 Jun 2004 19:13

38 lines
2510 bytes

On Wed, 09 Jun 2004 07:32:21 +0200, Aquila wrote:

> Jim wrote:
> 
>> bag container[bags_to_use];��//�A�declared�bag�of�arrays.
>> 
>> 
>> 
> 
> you don't want to write an output operator for just this array right?
> 
>> ostream& operator <<(ostream& outs, const bag& container[bags_to_use])
>> {
>> 
>> stuff I will write later.
>> 
>> }
>> 
>> but I think that I may be wrong?��Is�my�syntax�wrong?
>> 
> I don't think it's possible to have a variable array size in a definition...
> if it does work: did you put this operator in your class? what errors do you
> get?

It is perfectly possible. An array is a pointer to the first element in
c++. Just leave the [], and do some pointer arithmetic...
ostream& operator <<(ostream& outs, bag* container);

It is though easier to use a vector, and traverse with iterators.
vector <bag> container;
ostream& operator <<(ostream& outs, const vector<bag>& container);

If you place the << operator in your class declaration you will need a
friend with ostream. I don't think it is necessary if you don't place it
in the declaration of your bag class.

Greetz Matata

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