C++ Logo

STD-PROPOSALS

Advanced search

Subject: Re: [std-proposals] Allowing access to object representations
From: Krystian Stasiowski (sdkrystian_at_[hidden])
Date: 2019-08-18 19:52:42


Ok, I've gone through the issues that have brought up, here's a link to the
draft for R1 (unfortunately, I can only provide the raw text for it, on
vacation right now so I am unable to make the pdf):

In short, I changed [intro.object] p9 to specify that elements of an object
representation can be overlap (the nested within relationship, in my
opinion doesn't make sense, since the object representation "overlays" the
object, and several elements of object representations can overlay each
other), changed [expr.add] p6 to allow for pointer addition and subtraction
for pointers of type char, unsigned char, and std::byte (unsigned char
included since char and byte are their own object representations) pointing
to an element of an object representation, extended the nested within
guarantee to objects of nonzero size, and extended to definition of
contiguous layout objects to multi-dimensional arrays (since array elements
are contiguously allocated http://eel.is/c++draft/dcl.array#6)

On Sun, Aug 18, 2019 at 9:41 AM sdkrystian <sdkrystian_at_[hidden]> wrote:

> Although, it would still be contiguous; http://eel.is/c++draft/dcl.array#6
>
> Perhaps extending the definition to cover multidimensional arrays would be
> worth doing.
>
>
>
> Sent from my Samsung Galaxy smartphone.
>
> -------- Original message --------
> From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]>
> Date: 8/18/19 08:34 (GMT-05:00)
> To: std-proposals_at_[hidden]
> Cc: Language Lawyer <language.lawyer_at_[hidden]>
> Subject: Re: [std-proposals] Allowing access to object representations
>
> And multidimensional array of, say, `unsigned char` is its own object
> representation?
> If so, this does not match the expectation that the object representation
> is contiguous.
>
> On 18/08/2019 03:33, sdkrystian via Std-Proposals wrote:
> > Yes, in which case it is its own object representation
> >
> >
> >
> > Sent from my Samsung Galaxy smartphone.
> >
> > -------- Original message --------
> > From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]>
> > Date: 8/17/19 20:30 (GMT-05:00)
> > To: std-proposals_at_[hidden]
> > Cc: Language Lawyer <language.lawyer_at_[hidden]>
> > Subject: Re: [std-proposals] Allowing access to object representations
> >
> > Ah, so the object representation of an object of type T is a sequence of
> `unsigned char` objects unless T is (cv-qualified) `char` or `std::byte`
> (or array thereof)?
> >
> > On 18/08/2019 03:24, sdkrystian via Std-Proposals wrote:
> > > Same thing applies. I'll have to change [expr.add]/6 to make it work.
> > >
> > >
> > >
> > > Sent from my Samsung Galaxy smartphone.
> > >
> > > -------- Original message --------
> > > From: Language Lawyer via Std-Proposals <
> std-proposals_at_[hidden]>
> > > Date: 8/17/19 20:21 (GMT-05:00)
> > > To: std-proposals_at_[hidden]
> > > Cc: Language Lawyer <language.lawyer_at_[hidden]>
> > > Subject: Re: [std-proposals] Allowing access to object representations
> > >
> > > And for an object `a` of type `char`?
> > >
> > > On 18/08/2019 03:18, sdkrystian via Std-Proposals wrote:
> > > > The object representation of the object is itself... For an object
> `a` of type unsigned char, it's object representation is `a`
> > > >
> > > >
> > > >
> > > > Sent from my Samsung Galaxy smartphone.
> > > >
> > > > -------- Original message --------
> > > > From: Language Lawyer via Std-Proposals <
> std-proposals_at_[hidden]>
> > > > Date: 8/17/19 16:49 (GMT-05:00)
> > > > To: std-proposals_at_[hidden]
> > > > Cc: Language Lawyer <language.lawyer_at_[hidden]>
> > > > Subject: Re: [std-proposals] Allowing access to object
> representations
> > > >
> > > > > The object representation of an object of type unsigned char,
> char, std::byte, or an array of such types (ignoring cv-qualification), is
> itself.
> > > >
> > > > What does this cryptic "is itself" mean?
> > > > --
> > > > Std-Proposals mailing list
> > > > Std-Proposals_at_[hidden]
> > > > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
> > > >
> > > --
> > > Std-Proposals mailing list
> > > Std-Proposals_at_[hidden]
> > > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
> > >
> > --
> > Std-Proposals mailing list
> > Std-Proposals_at_[hidden]
> > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
> >
> --
> Std-Proposals mailing list
> Std-Proposals_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
>



STD-PROPOSALS list run by herb.sutter at gmail.com

Standard Proposals Archives on Google Groups