Ive got a (probably)dumb question here.

What is a void? I thought it was nothing.
It seems that in D it has a new meaning.

For example, how do I call this method?

aMethod(void[] buf)
{
}

It seems to me that I should need a char[]

I had a quick look at  the digtalsmars/d
but couldnt see it, and URL's or quick
tutorials via here, would be great :o))

Thanks for any help.

Phill.

>Ive got a (probably)dumb question here.
>
>What is a void? I thought it was nothing.
>It seems that in D it has a new meaning.
>
>For example, how do I call this method?
>
>aMethod(void[] buf)
>{
>}

Interesting. In C a pointer to void was used for some kind of generic
programming. E.g. malloc/free (C's way to dynamically (de)allocate memory) used
this:

void * malloc (size_t);
void free (void * ptr);


Type * memory = (Type *)malloc(size);
..
free (memory);


But I don't know what void-arrays could be used for in D.

Where do you see this method ?  You cant have an array of void , but usually 'void *' just means ( a chunk of data, no specified type ).  It's useful for manipulating raw data, coming in from sockets for example.  Marking a function as returning void means return nothing ( it is confusing now that u mention it, its just been around so long nobody thinks about it :) )

C

On Thu, 4 Mar 2004 20:22:17 +1100, Phill <phill@pacific.net.au> wrote:

> Ive got a (probably)dumb question here.
>
> What is a void? I thought it was nothing.
> It seems that in D it has a new meaning.
>
> For example, how do I call this method?
>
> aMethod(void[] buf)
> {
> }
>
> It seems to me that I should need a char[]
>
> I had a quick look at  the digtalsmars/d
> but couldnt see it, and URL's or quick
> tutorials via here, would be great :o))
>
> Thanks for any help.
>
> Phill.
>
>
>



-- 
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

Phill wrote:

> Ive got a (probably)dumb question here.
> 
> What is a void? I thought it was nothing.
> It seems that in D it has a new meaning.
> 
> For example, how do I call this method?
> 
> aMethod(void[] buf)
> {
> }
> 
> It seems to me that I should need a char[]
> 
> I had a quick look at  the digtalsmars/d
> but couldnt see it, and URL's or quick
> tutorials via here, would be great :o))
> 
> Thanks for any help.
> 
> Phill.
> 

It's actually a nice feature that allows you to have an array of any type, for example:

int[1] test;
void[] v = test;
printf("v.length = %d", v.length);

Prints out 4, without needing to cast or do length * size math. I used void[] in the send and receive methods of my Socket class.

-- 
Christopher E. Miller

Hmm, I didnt know you could have an array of void.  I distinctly remember the compielr telling me I couldn't.  My mistake :S.

C

On Thu, 04 Mar 2004 17:59:05 -0500, Vathix <vathix@dprogramming.com> wrote:

> Phill wrote:
>
>> Ive got a (probably)dumb question here.
>>
>> What is a void? I thought it was nothing.
>> It seems that in D it has a new meaning.
>>
>> For example, how do I call this method?
>>
>> aMethod(void[] buf)
>> {
>> }
>>
>> It seems to me that I should need a char[]
>>
>> I had a quick look at  the digtalsmars/d
>> but couldnt see it, and URL's or quick
>> tutorials via here, would be great :o))
>>
>> Thanks for any help.
>>
>> Phill.
>>
>
> It's actually a nice feature that allows you to have an array of any type, for example:
>
> int[1] test;
> void[] v = test;
> printf("v.length = %d", v.length);
>
> Prints out 4, without needing to cast or do length * size math. I used void[] in the send and receive methods of my Socket class.
>



-- 
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

C wrote:

> Hmm, I didnt know you could have an array of void.  I distinctly remember the compielr telling me I couldn't.  My mistake :S.
> 
> C
> 

It's not like a regular array though; since it has no defined type, you can't index or slice it. Maybe that was the error you got.

-- 
Christopher E. Miller

"Vathix" <vathix@dprogramming.com> wrote in message news:c28cbo$1oom$1@digitaldaemon.com...
> Phill wrote:
>
> > Ive got a (probably)dumb question here.
> >
> > What is a void? I thought it was nothing.
> > It seems that in D it has a new meaning.
> >
> > For example, how do I call this method?
> >
> > aMethod(void[] buf)
> > {
> > }
> >
> > It seems to me that I should need a char[]
> >
> > I had a quick look at  the digtalsmars/d
> > but couldnt see it, and URL's or quick
> > tutorials via here, would be great :o))
> >
> > Thanks for any help.
> >
> > Phill.
> >
>
> It's actually a nice feature that allows you to have an array of any type, for example:
>
> int[1] test;
> void[] v = test;
> printf("v.length = %d", v.length);
>
> Prints out 4, without needing to cast or do length * size math. I used void[] in the send and receive methods of my Socket class.

Yes thanks, very much, that is exactly where I
have seen it.
So I take it I can use a char[] instead of your int
example?

Thanks Phill.


> --
> Christopher E. Miller

yep Im aware of void (nothing) :o))
Its just an array of nothing that had me confused

Phill.


"C" <dont@respond.com> wrote in message news:opr4crhxpfehmtou@localhost... Where do you see this method ?  You cant have an array of void , but usually 'void *' just means ( a chunk of data, no specified type ).  It's useful for manipulating raw data, coming in from sockets for example. Marking a function as returning void means return nothing ( it is confusing now that u mention it, its just been around so long nobody thinks about it :) )

C

On Thu, 4 Mar 2004 20:22:17 +1100, Phill <phill@pacific.net.au> wrote:

> Ive got a (probably)dumb question here.
>
> What is a void? I thought it was nothing.
> It seems that in D it has a new meaning.
>
> For example, how do I call this method?
>
> aMethod(void[] buf)
> {
> }
>
> It seems to me that I should need a char[]
>
> I had a quick look at  the digtalsmars/d
> but couldnt see it, and URL's or quick
> tutorials via here, would be great :o))
>
> Thanks for any help.
>
> Phill.
>
>
>



--
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

"Vathix" <vathix@dprogramming.com> wrote in message news:c28cbo$1oom$1@digitaldaemon.com...
> Phill wrote:
>
> > Ive got a (probably)dumb question here.
> >
> > What is a void? I thought it was nothing.
> > It seems that in D it has a new meaning.
> >
> > For example, how do I call this method?
> >
> > aMethod(void[] buf)
> > {
> > }
> >
> > It seems to me that I should need a char[]
> >
> > I had a quick look at  the digtalsmars/d
> > but couldnt see it, and URL's or quick
> > tutorials via here, would be great :o))
> >
> > Thanks for any help.
> >
> > Phill.
> >
>
> It's actually a nice feature that allows you to have an array of any type, for example:
>
> int[1] test;
> void[] v = test;
> printf("v.length = %d", v.length);
>
snip

From that code :

test.length  would equal 1 and
v.length would equal 4;

Do  you agree that this is inconsistent?
Is there a reason for this, or is it a bug(which I doubt)?

Phill.

> --
> Christopher E. Miller

Phill wrote:

> "Vathix" <vathix@dprogramming.com> wrote in message
> news:c28cbo$1oom$1@digitaldaemon.com...
>
>> Phill wrote:
>>
>>
>>> Ive got a (probably)dumb question here.
>>>
>>> What is a void? I thought it was nothing.
>>> It seems that in D it has a new meaning.
>>>
>>> For example, how do I call this method?
>>>
>>> aMethod(void[] buf)
>>> {
>>> }
>>>
>>> It seems to me that I should need a char[]
>>>
>>> I had a quick look at  the digtalsmars/d
>>> but couldnt see it, and URL's or quick
>>> tutorials via here, would be great :o))
>>>
>>> Thanks for any help.
>>>
>>> Phill.
>>>
>>
>> It's actually a nice feature that allows you to have an array of any
>> type, for example:
>>
>> int[1] test;
>> void[] v = test;
>> printf("v.length = %d", v.length);
>>
>
> snip
>
> From that code :
>
> test.length  would equal 1 and
> v.length would equal 4;
>
> Do  you agree that this is inconsistent?
> Is there a reason for this, or is it a bug(which I doubt)?
>
> Phill.


Not really inconsistent. This gives the same output, just requires the cast:

int[1] test;
byte[] v = cast(byte[])test;
printf("v.length = %d", v.length);

-- 
Christopher E. Miller