Nice surprise with C++11

[Daniel Gutson]

I have been desperately busy to fix this, though we are indeed
interested in the fix since we'll use C++14 soon.
That's why I will address this a bit later. Sorry the delay.

   Daniel.

On Wed, Aug 5, 2015 at 7:36 PM, Daniel Gutson
<daniel.gutson at tallertechnologies.com> wrote:
> On Fri, Jul 31, 2015 at 9:56 AM, Sebastian Huber
> <sebastian.huber at embedded-brains.de> wrote:
>>
>>
>> On 31/07/15 14:51, Daniel Gutson wrote:
>>>
>>>
>>> > Is it possible to construct objects without an address via plain C++?
>>>
>>> Sorry I don't understand the question. Rephrase please?
>>>
>>> Global objects and objects of static storage duration don't take an
>>> address.
>>>
>>
>> This register asm variable has no address, since this is a real register.
>> This, however, is not a problem:
>>
>> int *h(void)
>> {
>>     register int i;
>>     return &i;
>>
>> }
>
> The 'register' keyword is deprecated since C++11.
> Additionally, C++ requires that all objects have unique addresses, that's why
> struct X{};
> sizeof(X) > 0
>
> (and that's why the "empty ase class optimization" idiom exists).
>
> Moreover, taking the address of an object prevents such object to
> dwell in a register.
>
> In your example, even in previous C++ versions, should prevent the
> 'register' hint to be honored,
> thus returning a temporal address to the stack (which would be invalid
> in the caller's context).
>
> So the short answer is NO.
>
> Did I answer your question? Is there any case this should be possible?
> (consider that I'm pursuing
> new C++ features for embedded systems in the C++ committee).
>
>    Daniel.
>
>>
>> --
>> Sebastian Huber, embedded brains GmbH
>>
>> Address : Dornierstr. 4, D-82178 Puchheim, Germany
>> Phone   : +49 89 189 47 41-16
>> Fax     : +49 89 189 47 41-09
>> E-Mail  : sebastian.huber at embedded-brains.de
>> PGP     : Public key available on request.
>>
>> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>>
>
>
>
> --
>
> Daniel F. Gutson
> Chief Engineering Officer, SPD
>
> San Lorenzo 47, 3rd Floor, Office 5
> Córdoba, Argentina
>
> Phone:   +54 351 4217888 / +54 351 4218211
> Skype:    dgutson
> LinkedIn: http://ar.linkedin.com/in/danielgutson



-- 

Daniel F. Gutson
Chief Engineering Officer, SPD

San Lorenzo 47, 3rd Floor, Office 5
Córdoba, Argentina

Phone:   +54 351 4217888 / +54 351 4218211
Skype:    dgutson
LinkedIn: http://ar.linkedin.com/in/danielgutson