C / C++ / MFC

1-Mar-01 22:46

A quick C++ language question for you experts - if I have a class X with no default destructor, and I want to declare an array of Xs as a member of class Y, how do I do it - the Xs must be initialised in the constructor initialiser list of Y:Y(), but there doesn't seem to be a way of initialising an array in a constructor initialiser list, although I've searched Stroustrup etc. and it doesn't specifically say that you can't do it, just doesn't say how.

Any offers
Dave

Dave

l a u r e n1-Mar-01 23:15

NO NO NO - I'm not the idiot !

1-Mar-01 23:15

so u want to embed a class within another class and init some array in the embedded class?

just write a constructor for the embedded class that fills the array with the necessary values

"every year we invent better idiot proof systems and every year they invent better idiots"

Dave Midgley1-Mar-01 23:46

Re: NO NO NO - I'm not the idiot !

1-Mar-01 23:46

I want to embed an array of objects of type X in class Y. Why don't you read the question? I also don't like being called an idiot by someone who apparently can't read, and apparently can't write either.

Dave

Dave

.::RockNix::.2-Mar-01 0:10

.::RockNix::.

2-Mar-01 0:10

You could try init your array of objects in a loop or something like this:

ClassX *MyClassXObejcts[SIZE];

for ( int x=0 ; x < = SIZE-1 ; x++ )

MyClassXObjects[x] = new ClassX( .... );

Now you will call the constructor of ClassX size-times. Within every call of the constructor you can init each ClassX own array.

Hope that is what you are looking for

Greatings Mario ///

----------------------
www.klangwerker.de
mario@klangwerker.de
----------------------

Dave Midgley2-Mar-01 0:17

2-Mar-01 0:17

Yes indeed - that is actually what I have done to 'get around' the problem. But I am puzzled that I can't do what I actually want to do, which is initialise the array in the initialiser list. It isn't even possible to initialise an array of integers in the initialiser list, and this seems to me to be a 'hole' in the language definition.

Dave

Simon Capewell2-Mar-01 2:30

Simon Capewell

2-Mar-01 2:30

It's kind of a hole, but filling it would cause inconsistancies

class X
{
X(char* c);
};

class Y
{
Y() : ???
{}

X x[100];
}

How would we specify the initializer for all the elements in x?
x("Blah") tries to apply the constructor for X on the array itself - a type mismatch. You are also only able to initialise all the elements to the same value, which you can do with a default constructor on X anyway.

x[0]("Blah"), x[1]("Blah")... initialises each element individually, which would be pretty tedious for a very large array!

So the best solution was to not provide a mechanism for doing this and force you to workaround the problem.

Simon

Dave Midgley2-Mar-01 3:52

2-Mar-01 3:52

Thanks Simon, that makes sense. The main thing is you've confirmed that it can't be done, and it's not just that I couldn't find out how to do it.
I appreciate your making the point about signatures too, in your other message. Thanks.

Dave

Dave Midgley2-Mar-01 3:53

Re: NO NO NO - I'm not the idiot !

2-Mar-01 3:53

l a u r e n2-Mar-01 1:06

2-Mar-01 1:06

hey fukwit
i didnt call you an idiot (although maybe i should have)
i read the question and tried to help ... if i misunderstood then maybe you should phrase it better
we don't get paid to answer your dumbass questions here ... if i got it wrong just say so politely

"every year we invent better idiot proof systems and every year they invent better idiots"

Apology

Dave Midgley2-Mar-01 3:44

2-Mar-01 3:44

I apologise. Your signature just looks like part of the message, especially when the message is relayed as e-mail, and I read it as such, and reacted just as you did to mine.

Dave

l a u r e n2-Mar-01 3:51

2-Mar-01 3:51

groovy ... nuff said
no offence meant here either
Smile | :)

lauren

"every year we invent better idiot proof systems and every year they invent better idiots"

this opinion is purely mine and has no relationship to any persons living or dead

Erik Funkenbusch2-Mar-01 14:40

Erik Funkenbusch

2-Mar-01 14:40

Perhaps you should use usenet ettiquette for your signature, which is to seperate the signature from the message by 3 dashes (---).

---
This is a stupid signature...

3-Mar-01 9:40

What would she care about anyways? The signature shows her metality!

Christian Graus3-Mar-01 9:52

Christian Graus

3-Mar-01 9:52

And your anonymous post speaks volumes about yours.

I think it's *damn* funny, but then, I have a sense of humour.

Christian

The content of this post is not necessarily the opinion of my yadda yadda yadda.

To understand recursion, we must first understand recursion.

jesus christ ... enough already!

3-Mar-01 10:01

And your anonymous post speaks volumes about yours.

Yes! But not a bad one at all! Big Grin | :-D

I think it's *damn* funny, but then, I have a sense of humour.

Again, Yes! You're right! Big Grin | :-D

One thing though, why would she reply on any issue she got no clues?
Look at all the replies she posts, it is almost every where on every question? Nothing but just a reply! Wink | ;)

l a u r e n3-Mar-01 10:12

3-Mar-01 10:12

my final comment on this thread ... true on some issues i have no definitive answer but i post a reply for 3 main reasons:
1). if a thread goes unanswered for a while it seems to get ignored
2). so the poster knows there are people out here who are reading what they post
3). i usually have a clue as to how to solve the issue in one way ... it might not be the best way but it would usually work ... if others can correct me or answer more precisely so much the better ... if not then at least the poster can get a start on maybe a fresh way of thinking ... i always think that some lead is better than none

as for your seemingly personal comments ... you have no idea about me or who i am so please refrain from guessing and concluding derogatory things from your guesses

fyi i have been coding for 20 years and can write in most languages on most os's ... when you have as much experience maybe you'll understand that advice does not always have to relate to the minutae of exact technologies

i would comment on how many times you try to help others but as you post anonymously i can't tell

Suspicious | :suss:

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"every year we invent better idiot proof systems and every year they invent better idiots"