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I'm a little confused. I have a class function declared like:

const CItem& operator << (const std::string &sIn);

Which I use like this:

CItem Item;
Item << "blaster01,1,0,...,0,0,20,0,0,20,eol";

At the end of the method it does:
return *this;

My question is, is my const on the return value doing anything? I don't
know why I even have it there (maybe I copied this method from some source).

const CItem& seems to be to define a reference to a CItem that is constant.
Is that correct? Item is not declared as const, however. Maybe with the
way I'm using this thing I don't need to return any value at all anyway?

"Rolf Magnus" <> wrote in message
news:e3uq9a$c50$02$...
> Jim Langston wrote:
>
>> I'm a little confused. I have a class function declared like:
>>
>> const CItem& operator << (const std::string &sIn);
>>
>> Which I use like this:
>>
>> CItem Item;
>> Item << "blaster01,1,0,...,0,0,20,0,0,20,eol";
>>
>> At the end of the method it does:
>> return *this;
>>
>> My question is, is my const on the return value doing anything?
>
> Well, you won't be able to chain the operator calls, like:
>
> Item << "Hello, " << "world";
>
> Basically, returning the reference at all doesn't make much sense if it's
> const.
>
>> I don't know why I even have it there (maybe I copied this method from
>> some source).
>>
>> const CItem& seems to be to define a reference to a CItem that is
>> constant.
>> Is that correct?
>
> Yes.

Okay, so this begs the question, should I even be overriding the operator <<
anyway? If I'm not returning anything, maybe it would be better to just
make a function like

void LoadFromString( const std::string& sIn )

Jim Langston wrote:

> I'm a little confused. I have a class function declared like:
>
> const CItem& operator << (const std::string &sIn);
>
> Which I use like this:
>
> CItem Item;
> Item << "blaster01,1,0,...,0,0,20,0,0,20,eol";
>
> At the end of the method it does:
> return *this;
>
> My question is, is my const on the return value doing anything?

Well, you won't be able to chain the operator calls, like:

Item << "Hello, " << "world";

Basically, returning the reference at all doesn't make much sense if it's
const.

> I don't know why I even have it there (maybe I copied this method from
> some source).
>
> const CItem& seems to be to define a reference to a CItem that is
> constant.
> Is that correct?

Yes.