[swift-users] When does `Data.init?(capacity:)` fail?

[Saagar Jha]

Not quite:

Swift’s policy on memory allocation failure is that fixed-size object
allocation is considered to be a runtime failure if it cannot be handled.
OTOH, APIs that can take a variable and arbitrarily large amount to
allocate should be failable. NSData falls into the later category.

Source <http://article.gmane.org/gmane.comp.lang.swift.user/1709>


On Sun, Jun 19, 2016 at 10:00 AM Karl <razielim at gmail.com> wrote:

> As I understand it, that’s not an error in the ‘try’ sense of the word. If
> that failure happens, it’s a catastrophic issue which should bring down the
> application.
>
> So the initialiser shouldn’t be failable; you’re right. File a bug at
> bugs.swift.org.
>
> Karl
>
> On 18 Jun 2016, at 06:06, Saagar Jha via swift-users <
> swift-users at swift.org> wrote:
>
> This <http://article.gmane.org/gmane.comp.lang.swift.user/1702> might be
> relavant. Basically, Data’s init will fail if memory can’t be allocated
> for it.
>
>
> On Fri, Jun 17, 2016 at 11:38 AM Adrian Zubarev via swift-users <
> swift-users at swift.org> wrote:
>
>> Hello there, I’m trying to optimize my code and reduce copying from
>> different buffers into a new one.
>>
>> I thought I just create a Data value with enough capacity and write
>> directly into it. My problem is that Data.init?(capacity:) can fail, but
>> why and when?
>>
>> Can someone explain this behavior to me?
>>
>> I’m sending data via TCP sockets and when recn function write directly
>> into a Data struct.
>>
>>
>>
>> --
>> Adrian Zubarev
>> Sent with Airmail
>>
>> _______________________________________________
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>>
> --
> -Saagar Jha
> _______________________________________________
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>
>
> --
-Saagar Jha
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