Title
<cstdalign> and #define of alignof
Status
resolved
Section
[support.runtime]
Submitter
Richard Smith

Created on 2013-02-14.00:00:00 last changed 95 months ago

Messages

Date: 2016-06-28.13:53:39

[ 2016-03 Oulu ]

P0063 was adopted.

Change status to Tentatively Resolved

Date: 2016-03-08.22:51:25

[ 2016-03 Jacksonville ]

Walter: this is on track to go away if we adopt Clark's paper to rebase to C11
Room: tentatively resolved; revisit after C11 paper: P0063

Date: 2014-02-15.00:00:00

[ 2014-02-15 Issaquah ]

STL: related to earlier issue on C4, 2201, and now we get a C11 header
JY: find _Alignof as keyword C11 FDIS has four defines in stdalign.h
AM: need paper for C11 as base library we should really do that
STL: really need vendor input
STL: don't think we need to do anything right now not P1
AM: any objections to downscale to P2 (no objections)

Date: 2013-02-14.00:00:00

According to [support.runtime] p2:

The contents of these headers are the same as the Standard C library headers [..], <stdalign.h>, [..]

Since our base C standard is C99, which doesn't have a <stdalign.h>, the reference to a non-existing C header is irritating (In this context <stdalign.h> doesn't refer to the deprecated C++ header <stdalign.h> described in [depr.c.headers]).

Furthermore, it would be also important that it doesn not define a macro named alignof, which C11 also defines in this header.

Currently we only have the following guarantee as part of [support.runtime] p7:

The header <cstdalign> and the header <stdalign.h> shall not define a macro named alignas.

It is unclear what the better strategy is: Striking the reference to <stdalign.h> in [support.runtime] p2 or upgrading to C11 as new base C standard.

History
Date User Action Args
2016-06-28 13:53:39adminsetmessages: + msg8212
2016-06-28 13:53:39adminsetstatus: open -> resolved
2016-03-08 22:51:25adminsetmessages: + msg8022
2014-03-03 13:52:20adminsetmessages: + msg6894
2014-03-03 13:52:20adminsetstatus: new -> open
2013-02-14 00:00:00admincreate