«

valarray<bool> va1(10);

// Initialize va1 here?

valarray<bool> va2 (80);

va2 = va1;

Do we have to initialize va1 like using for loop above (since if not, the
printout of va1 will display garbage)?

Can va1 be initialized like "valarray<bool> va1(10, false);" when defining
it?

Is it ok to assign va1 to va2? Does va2 have to be specified with a size
before assigning va1 to it? Must the size of va2 be larger than va1?

Thanks!

"Busin" <> wrote in message
news:8T8Ec.158035$...
> valarray<bool> va1(10);
>
> // Initialize va1 here?
>
> valarray<bool> va2 (80);
>
> va2 = va1;
>
> Do we have to initialize va1 like using for loop above (since if not, the
> printout of va1 will display garbage)?

No, the elements of va1 will be default constructed. I believe for a bool
this should mean it will be set to false. Your compiler may not implement
this correctly though.

>
> Can va1 be initialized like "valarray<bool> va1(10, false);" when defining
> it?

No, like this

valarray<bool> val(false, 10);

>
> Is it ok to assign va1 to va2?

Yes

> Does va2 have to be specified with a size
> before assigning va1 to it?

No

> Must the size of va2 be larger than va1?

No, va2 will change its size to be the same as va1

john

On Tue, 29 Jun 2004 09:19:49 +0100, "John Harrison"
<> wrote:

>
>"Busin" <> wrote in message
>news:8T8Ec.158035$...
>> valarray<bool> va1(10);
>>
>> // Initialize va1 here?
>>
>> valarray<bool> va2 (80);
>>
>> va2 = va1;
>>
>> Is it ok to assign va1 to va2?
>
>Yes

No, it's undefined behaviour, since the lengths don't match.

>> Does va2 have to be specified with a size
>> before assigning va1 to it?
>
>No

Yes.

>> Must the size of va2 be larger than va1?
>
>No, va2 will change its size to be the same as va1

The sizes of va2 and va1 must be exactly the same. See 26.3.2.2.

Tom
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"tom_usenet" <> wrote in message
news:...
> On Tue, 29 Jun 2004 09:19:49 +0100, "John Harrison"
> <> wrote:
>
> >
> >"Busin" <> wrote in message
> >news:8T8Ec.158035$...
> >> valarray<bool> va1(10);
> >>
> >> // Initialize va1 here?
> >>
> >> valarray<bool> va2 (80);
> >>
> >> va2 = va1;
> >>
> >> Is it ok to assign va1 to va2?
> >
> >Yes
>
> No, it's undefined behaviour, since the lengths don't match.
>
> >> Does va2 have to be specified with a size
> >> before assigning va1 to it?
> >
> >No
>
> Yes.
>
> >> Must the size of va2 be larger than va1?
> >
> >No, va2 will change its size to be the same as va1
>
> The sizes of va2 and va1 must be exactly the same. See 26.3.2.2.
>

OK, must have been getting confused with vector. Apologies.

john