Doc No:   SC22/WG21/N1715
                                                  J16/04-0155
                                        Date:     October 22, 2004
                                        Project:  JTC1.22.32
                                        Reply to: Robert Klarer
                                                  IBM Canada, Ltd.
                                                  [email protected]

Minutes of J16 Meeting No. 39/WG21 Meeting No. 34, October 17-22, 2004

1. Opening activities

1.1 Opening comments

1.2 Introductions

1.3 Membership, voting rights, and procedures for the meeting

1.4 Agenda review and approval

Clamage presented the agenda (document 04-0138/N1698).

Motion to approve the agenda:

1.5 Distribution of position papers, WG progress reports, WG work plans for the week, and other documents that were not distributed before the meeting.

Core Working Group (CWG)

Library Working Group (LWG)

Plauger recommended a motion on Friday to appoint a subgroup to edit and review the TR after this meeting.

Evolution Working Group (EWG)

1.6 Approval of the minutes of the previous meeting

Motion to approve the minutes (document 04-0069/N1629):

1.7 Report on the WG21 Sunday meeting

It was agreed Sunday night that there will be two evening sessions. The first of these will be conducted Monday night from 7:30pm to 10:30pm, and will be conducted in three parts:

• Hash Tables, presented by Ami Tavory and chaired by Austern
• Policy-Based Smart Pointers, presented by Andrei Alexandrescu and chaired by Austern
• A Memory Model for Multithreaded C++, presented by Alexandrescu and chaired by Glassborow

The presentation on A Memory Model for Multithreaded C++ will start at 9:00pm sharp.

The second evening session will be conducted by Stroustrup from 7:30pm to 10:30pm on Wednesday night. It will deal with the categorization of related EWG proposals into clusters (see 1.5, above).

Benito reported on the SC22 plenary, held in Jeju City, South Korea, and at which he represented both WG14 and WG21. At the plenary, Austern was approved as Project Editor for library TR1, Becker was approved as Project Editor for the Working Draft of the C++ Standard, and Plauger was approved as Project Editor for the TR on Decimal Arithmetic.

As well, Benito noted that WG15 and WG20 have been disbanded.

Sutter reported that 8 countries were officially represented at this meeting, and that the drafting committee for this meeting was composed of Adamczyk, Austern, Glassborow, and Ottosen.

1.8 Liaison reports

WG14 Liaison

• in Sydney, WG14 approved TC2
• a new Work Item for a secure C library has been approved.
• TR19769 on new character data types is complete
• a new Work Item for special math functions is under way
• the two TRs that WG14 has already published will be made available on JTC website
• A new C standard that consists in the C99 standard with Technical Corrigenda 1 and 2 applied to it will be published by WG14.

Dos Reis asked whether an electronic company of C90 is available. Benito replied that, to his knowledge, no reliable and correct electronic copy exists.

TG5 Liaison

Plum reminded the committee that all WG21 members are invited to attend TG5 meetings as liaisons.

Plum described the outcome of a particularly controversial technical issue with respect to native types. CLI has builtin data types with specific sizes. These may sizes may not correspond with those of the corresponding types on the native platform. The solution that has been adopted is to make the mapping between CLI types and a platform's native types implementation defined.

1.9 Editor's report and WP approval

Becker reported that N1638 is the last revision of the Working Draft to be formatted using TROFF, while N1655 is the first Working Draft to use LaTex. For the forseeable future, subsequent revisions will use continue to use LaTex. Every page of N1655 has been reviewed by at least one member of the committee. The same toolset is now being used to prepare both the Working Draft and the Library TR. both

Motion to accept the working paper (document 04-00xx/N1655):

Motion to accept TR working draft (document 04-00xx/N1687) as the working paper for TR work:

1.10 New business requiring actions by the committee

2. Organize subgroups, establish working procedures.

We have three subgroups: Core, Library, and Evolution.

The committee broke into subgroups at 10:17 (GMT-8:00).

3. WG sessions (Core, Library, Performance, Evolution).

4. WG sessions continue.

5. WG sessions continue.

6. General session.

6.1 WG status and progress reports.

Core Working Group

Adamczyk presented Core Working Group (CWG) status and formal motions to be made Friday (for formal motions, see 8.1, below).

The CWG received 15 new issues since the last meeting. At this meeting, 15 issues will be promoted by formal motion to DR status. As well, the CWG ruled that 5 defects were NAD.

The CWG reviewed 4 EWG proposals and recommended minor changes to the proposed wording in each case. These issues will be moved into Ready state, and will be moved for formal acceptance at the next meeting. The issues that have moved into ready state are:

• static_assert
• long long
• Extended friend declarations
• Preprocessor synchronization with C99

Adamczyk noted that, while the long long proposal makes the result of unsuffixed decimal constants that are too large for long long but not for unsigned long long undefined, the CWG decided to make them ill-formed. This is consistent with WG14's resolution to their own DR 298, which Adamczyk submitted on this topic.

Adamczyk reviewed the CWG's proposed resolution to issue 391. This resolution will require the direct binding of references-to-const to class rvalues.

Library Working Group

Austern presented Library Working Group status and reviewed formal motions to be made Friday (for formal motions, see 8.1, below).

The vast majority of changes that will be voted into TR1 at this meeting are of minor technical importance.

Default-initialized Regular Expressions

Austern reviewed the LWG's proposed resolution to TR issue 7.28. This issue deals with the question of what guarantees can be made about default-initialized regular expressions. The resolution rules that the expression regex() is equivalent to regex(""). Algorithms would not be required to check the validity of the regular expressions upon which they are operating.

Glassborow expressed concern that one could so easily produce a degenerate regular expression. Why not make it impossible for a novice user to make this error?

Becker noted that the behavior being proposed is the same as for pointers and iterators

Brown asked what might happen when a user tries to makes a vector of default-initialized regular expressions?

Other discussion ensued.

Nelson inquired about the test for validity. Is it necessary to remove it?

Becker reported that the complexity of the specification of the test for validity is prohibitive.

Glassborow indicated that the UK will comment on this issue on the PDTR ballot.

Nelson pointed out that, given that the UK promises to comment on this, we will have an opportunity to talk about it later.

Gregor suggested that, if the currently proposed resolution is adopted, the commitee can specify more sophisticated behavior later. This is a conservative approach, which may help the committee to avoid making a mistake that it is unable to correct later.

Glassborow recommended a straw poll on the question of whether the LWG should reconsider its direction on this issue. The results of the straw poll were as follows:

Straw Vote: advise LWG to reconsider the proposed resolution to TR issue 7.28?

Austern agreed that the LWG would reconsider its proposed resolution to TR issue 6.17.

Nominating an Editorial Committee to Review the Library Extensions TR

Austern reviewed a formal motion (see 8.1, below) concerning the appointment of an editorial committee and a review committee to apply and approve the changes to the library TR that have been accepted at this meeting, and to forward the document for concurrent ISO ballot.

Plauger asked the committee whether there was objection to the LWG selecting the editorial committee, and whether there were any volunteers.

Maurer suggested that, for the benefit of those who are not present, the formal motion should list the names of those that are named to the committees.

Plauger observed that two people have official standing with SC22: the Project Editor and the Convenor. They should be identified in the formal motion as being the individuals responsible for selecting contributors.

Austern noted that the editorial committee really only needs to be himself and Becker. Austern will 'volunteer' others for the review committee. The formal motion will be amended to name these volunteers.

Evolution Working Group

Evolution Working Group (EWG) will be making no formal motions Friday.

Stroustrup reported on EWG activities and progress.

In particular, Stroustrup reported that there was some controversy on the proposal to extend enum (paper N1579). There was a long debate, and a straw poll was held to determine interest in moving the proposal forward. The results of that straw poll were as follows:

strong favor	favor	oppose	strongly oppose
9	6	0	3

Stroustrup indicated that the proposed syntax was the main concern of those who registered strong opposal.

Stroustrup noted as well that the static_assert proposal (paper N1617) will be moved into Ready state.

Dos Reis observed that there was some controversy with respect to static_assert. Was it ready to be moved forward, given that there are other proposals whose intended purpose may partially overlap that of static_assert? Dos Reis' concern in moving static_assert forward is that this proposal should be considered together with some other proposals, such as those for concepts and Contract Programming.

Stroustrup replied that there is strong agreement in EWG that related propsals should be considered together. The question is whether static_assert is related to concepts and Contract Programming.

Ottosen recalled that, in Sydney, he was encouraged to work on his Contract Programming propsal, so he hopes that this proposal can be discussed by the EWG before static_assert is enshrined in the WP.

Crowl commented that there's no major capability introduced in the proposal, so there was no rush to vote static_assert into the WP.

Stroustrup pointed out that there was a desire to clear the EWG backlog, and static_assert is a proposal that has been around for a long time and enjoys strong support. That's why static_assert will be moved to Ready status.

Klarer observed that the proposal will be moved to Ready status, it will be not be voted into the WP at this meeting.

Future meetings:

See 9.1, below.

6.2 Presentation and discussion of DRs ready to be voted on. Straw votes taken.

7. WG sessions continue

8. Review of the meeting

8.1 Formal motions, including DRs to be resolved.

Stroustrup moved to thank the host. Applause.

Adamczyk moved that we thank Dinkumware, particularly Chris Walker for network support.

Core Working Group motions

Mover: Adamczyk

Seconder: Nelson

WG	favor	oppose	abstain
J16	17	0	0
WG21	8	0	0

Library Working Group motions

• Move to raise issues 405, 410, 412, 415, 425, 426, 432, 435, 441, 442, 443, 448, and 449 from N1684=04-0124 to DR status and apply them to the working paper.

  Mover: Austern

  Seconder: Hinnant

  
  

  WG	favor	oppose	abstain
  J16	17	0	0
  WG21	8	0	0

• Move to amend the library extension TR as specified in N1673=04-0113, "Unifying TR1 Function Object Type Specifications", by Pete Becker and Peter Dimov.

  Mover: Austern

  Seconder: Glassborow

  
  

  WG	favor	oppose	abstain
  J16	17	0	0
  WG21	8	0	0

• Move to amend the library extension TR as specified in N1723=04-0163, "Proposed resolutions to library TR issues", by Matt Austern.

  Mover: Austern

  Seconder: Brown

  
  

  WG	favor	oppose	abstain
  J16	17	0	0
  WG21	8	0	0

• Move to appoint an editorial committee consisting of Matt Austern and Pete Becker to apply the changes to the library extension TR and appoint a review committee consisting of Pete Becker, Walter Brown, Marc Paterno, and P. J. Plauger to approve the changes, and empower the convener to forward the document for ISO concurrent ballot.

  Mover: Austern

  Seconder: Glassborow

  
  

  WG	favor	oppose	abstain
  J16	17	0	0
  WG21	8	0	0

Evolution Working Group motions

None.

8.2 Review of action items, decisions made, and documents approved by the committee

None.

8.3 Issues delayed until Friday

None.

9. Plans for the future

9.1 Next meeting

Benito reported that the host has requested that members expecting to attend the meeting in Lillehammer, Norway make their reservations before the end of this year.

The following meeting will be held in Mont Tremblant, QC, Canada. Sutter reported that the dates for this meeting are Oct 2-7, 2005. Brown noted that this interferes with Rosh Hashanah. Sutter promised to contact Steve Michel to straighten this out.

Benito indicated that Germany is looking into hosting WG14, possibly in Berlin, in April 2006.

9.2 Mailings

Nelson reported that the deadline for the post-meeting mailing will be November 5, 2004, the deadline for the mid-term mailing will be January 7, 2005, and the deadline for the pre-Lillehammer meeting mailing will be March 4, 2005.

9.3 Following meetings

covered on Monday.

Motion to adjourn

Applause.

Meeting adjourned at 09:24(GMT-10:00)

Attendance