Standardization

N4573: February 2017 WG21 Meeting—Tom Plum

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N4573

Date: 2016-02-02

February 2017 WG21 Meeting

by Tom Plum

Excerpt:

The February 2017 WG21 meeting is sponsored by Plum Hall and the Standard C++ Foundation. The meeting will take place at the Royal Kona Resort, in Kailua-Kona Hawaii, Monday Feb 27 to Saturday Mar 04.

P0188R0: Wording for [[fallthrough]] attribute—Andrew Tomazos

New WG21 papers are available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: P0188R0

Date: 2016-01-03

Wording for [[fallthrough]] attribute

by Andrew Tomazos

Abstract:

Wording for the [[fallthrough]] attribute described in P0068R0 is proposed for application to the C++17 working draft. [[fallthrough]] captures an intent to use the feature of “falling-through” from one case block to the next, in a switch statement. It has heavy use in existing practice. Kona EWG voted SF=15, F=5, N=0, A=0, SA=0 in favor of [[fallthrough]] from P0068R0. See P0068R0 for detailed motivation/rationale.

P0187R0: Proposal of Bitfield Default Member Initializers—Andrew Tomazos

New WG21 papers are available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: P0187R0

Date: 2015-11-20

P0187R0: Proposal of Bitfield Default Member Initializers

by Andrew Tomazos

Abstract:

We propose default member initializers for bitfields. Example:

struct S {
  int x : 6 = 42;
};

To ease parsing we specify a rule, roughly summarized as “you have to use =, and = always starts the initializer”.

P0212: Wording for [[maybe_unused]] attribute—Andrew Tomazos

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: P0212R0

Date: 2016-01-31

Wording for [[maybe_unused]] attribute

by Andrew Tomazos

Excerpt:

A wording for the [[maybe_unused]] attribute is proposed for application to the C++17 Working Draft. The semantics of [[maybe_unused]] are the same as those described for [[unused]] in P0068R0 and presented to Kona EWG. Kona EWG voted SF=5, F=11, N=2, A=0, SA=0 in favor of the attribute.

See P0068R0 for detailed motivation/rationale.

P0207: Ruminations on lambda captures—Ville Voutilainen

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: P0207R0

Date: 2016-01-28

Ruminations on lambda captures

by Ville Voutilainen

Excerpt:

The proposal for capturing *this by value (P0018) raised suggestions for a "true value capture", which led to suggestions to change capture-default that defaults to by-value capture([=]) in the case of capturing class members. This paper explores what the suggested changes to the capture-default might mean. This paper specifically doesn't try to claim that any of the changes would have an effect on any particular amount of existing code, and admits that the examples in this paper are somewhat concocted and for illustrative purposes only. 

P0206R0: Discussion about std::thread and RAII—Ville Voutilainen

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: P0206R0

Date: 2016-01-27

Discussion about std::thread and RAII

by Ville Voutilainen

Excerpt:

C++ continues not to provide a thread type that would join() automatically on scope exit. This causes exception-safety problems, because failing to join() in all code paths causes the destructor of a std::thread to terminate(). This paper explores various ways to solve the problem.

N4570: June 2016 WG21 Meeting—Ville Voutilainen

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N4570

Date: 2016-01-18

June 2016 WG21 Meeting

by Ville Voutilainen

Excerpt:

The June 2016 WG21 meeting is sponsored by Symbio. The meeting will take place at the Radisson Blu Hotel, in Oulu, Finland, Monday Jun 20, 2016, to Saturday, Jun 25, 2016.

C++ Language Support for Pattern Matching and Variants—David Sankel

A discussion on the possibility for C++ language support for pattern matching and variants.

C++ Language Support for Pattern Matching and Variants

by David Sankel

From the article:

The C++ Programming Language needs a language based variant, or at least P0095R0 argued for it at the 2015 Kona C++ standardization meeting. P0095R0, however, didn’t fully explore generalized pattern matching, which is another desirable feature that is highly related. This post explores some ways to generalize the minimal pattern matching described in P0095R0.