Difference between variable declarations...

[pmatos]

Hi all,

What's the difference between:
int& i;

and

int i;

?

Cheers,

Paulo Matos

[Rolf Magnus]

pmatos wrote:

Hi all,

What's the difference between:
int& i;

and

int i;

?

The former is a reference to an integer, the latter is an integer.

[pmatos]

Got it, thanks. 5.5 of C++PL. :)

[Sharad Kala]

"Rolf Magnus" <ra******@t-online.de> wrote in message
news:d1*************@news.t-online.com...

pmatos wrote:

Hi all,

What's the difference between:
int& i;

and

int i;

?

The former is a reference to an integer, the latter is an integer.

Also former is not legal C++, a reference has to be initialized for sure.

Sharad

[Victor Bazarov]

Sharad Kala wrote:

"Rolf Magnus" <ra******@t-online.de> wrote in message
news:d1*************@news.t-online.com...

pmatos wrote:

Hi all,

What's the difference between:
int& i;

and

int i;

?

The former is a reference to an integer, the latter is an integer.

Also former is not legal C++, a reference has to be initialized for sure.

It us legal if it appears inside a class definition.

V

[Sharad Kala]

"Victor Bazarov" <v.********@comAcast.net> wrote in message

Also former is not legal C++, a reference has to be initialized for

sure.
It us legal if it appears inside a class definition.

Yes.
To OP: Even then you need to bind the reference in the initializer list.

Sharad

[Rolf Magnus]

Sharad Kala wrote:

"Rolf Magnus" <ra******@t-online.de> wrote in message
news:d1*************@news.t-online.com...

pmatos wrote:

> Hi all,
>
> What's the difference between:
> int& i;
>
> and
>
> int i;
>
> ?
The former is a reference to an integer, the latter is an integer.

Also former is not legal C++,

Wrong. The following should compile:

struct X
{
X(int& i) : i(i) {}

int& i;
};

int main()
{
int i = 3;
X x(i);
}
a reference has to be initialized for sure.

True.

[Sharad Kala]

"Rolf Magnus" <ra******@t-online.de> .

Also former is not legal C++,

Wrong.

Not totally wrong.
int main()
{
int& i; // Not legal
}

Given the context in which OP asked the question, it seemed that it was not
in a class definition. The point I was trying to stress was that you cannot
leave the reference uninitialized.

Sharad

[Rolf Magnus]

Sharad Kala wrote:

"Rolf Magnus" <ra******@t-online.de> .

>
> Also former is not legal C++,
Wrong.

Not totally wrong.
int main()
{
int& i; // Not legal
}

Well, can you name one language construct that can be used _everywhere_ in a
program?
Given the context in which OP asked the question, it seemed that it was
not in a class definition.
Actually, I don't see any context.
The point I was trying to stress was that you cannot leave the reference
uninitialized.

And I agreed to that.

[Alf P. Steinbach]

* Rolf Magnus:

Actually, I don't see any context.

Note the semicolon at the end in the Original Posting:

int& i;

This is only valid in a class definition.

But since the question was what does it mean, it probably doesn't
imply very much about context...

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

[pmatos]

Alf P. Steinbach wrote:

* Rolf Magnus:

Actually, I don't see any context.
Note the semicolon at the end in the Original Posting:

int& i;

This is only valid in a class definition.

But since the question was what does it mean, it probably doesn't
imply very much about context...

Indeed, I didn't want to know about context specific questions but I
didn't know it had to be initialized until before reading section 5.5
of C++PL. Anyway, I already understood what it is for. :)

Thanks a lot people and don't get mad about context specific
questions... :)

Cheers,

Paulo Matos
--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

[Rolf Magnus]

pmatos wrote:

Thanks a lot people and don't get mad about context specific
questions... :)

Nah, we don't. We're just nitpicking. That's what makes us nerds.
:-)