March 2014

N3914: Additional Core Language Issue Resolutions for Issaquah -- William M. Miller

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3914

Date: 2014-02-14

Additional Core Language Issue Resolutions for Issaquah

by William M. Miller

Excerpt:

The following issue resolutions, in addition to those in "ready" and "tentatively ready" status in document N3833, have been approved by the Core Language Working Group to be applied to the DIS.

C++ User Group Meetings in March

The montly overview about C++ User Group Meetings:

C++ User Group Meetings in March 2014

by Jens Weller

From the Article:

The full list of all meetings in march:

10.3 C++ UG Malmö, Sweden - C++folk/ C++11 Lightning talks
10.3 C++ UG Philadelphia - boost spirit
12.3 C++ UG San Francisco/Bayarea - Fun with Lamdas: C++14 Style
13.3 C++ UG Lyon, France
13.3 C++ UG Dresden - building Compilers in C++
17.3 C++ UG Belgium - Whats new in C++14
17.3 C++ UG London
17.3 C++ UG NRW/Dortmund
17.3 C++ UG Denver - C++11 Standard
18.3 C++ UG Berlin - Peter Gottschling - Matrix Template Library
18.3 C++ UG Hamburg
19.3 C++ UG NRW/Düsseldorf - Exception Safety guarantees in C++
19.3 C++ UG North West/Seattle - C++17: I see a monad in your future
20.3 C++ UG Munich - C++ IO Streams
25.3 C++ UG Chicago seems like they need a location!
27.3 C++ UG New York - C++14

N3908: Working Draft, C++ Extensions for Library Fundamentals -- Jeffrey Yasskin

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3908

Date: 2014-03-02

Working Draft, C++ Extensions for Library Fundamentals

by Jeffrey Yasskin

Excerpt:

This technical specification describes extensions to the C++ Standard Library (1.2). These extensions are classes and functions that are likely to be used widely within a program and/or on the interface boundaries between libraries written by different organizations.

N3903: C++ CD Comment Status Rev. 6 -- William M. Miller

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3903

Date: 2014-03-03

C++ CD Comment Status Rev. 6

by William M. Miller

Excerpt:

This document summarizes the status of WG21 after the 2014-02 (Issaquah) meeting in addressing National Body comments on Committee Draft document N3690.

In total, 85 comments were received. To date, 39 have been accepted as proposed, 21 have been accepted with modifications, 25 have been rejected, and 0 remain to be addressed.

N3901-2: Minutes (February 2014) WG21 and PL22.16 Meetings -- Kyle Kloepper

New WG21 papers are available. A copy of each is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3901-2

Date: 2014-03-03

Minutes (February 2014) WG21 Meeting No. 57

Minutes (February 2014) PL22.16 Meeting No. 62

by Kyle Kloepper

Excerpt:

WG21 motions:

WG21 motion 1: Move to appoint an editing committee composed of Daniel Krügler, Alisdair Meredith, Mike Miller, Bjarne Stroustrup, and Jeffrey Yasskin to approve the correctness of the C++ working paper as modified by the motions approved at this meeting, and to direct the Convener to transmit the approved updated C++ working paper to ITTF for DIS ballot.

Moved by: Hedquist

Seconded by: van Winkel

PL 22.16 unanimous consent 

WG21 unanimous consent

N3955: Group Member Specifiers -- Andrew Tomazos

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3955

Date: 2014-02-25

Group Member Specifiers

by Andrew Tomazos

Excerpt:

We propose allowing a space-separated sequence of specifiers to be placed after an access specifier in a class definition. The specifiers so placed are applied to each member declaration in the group following the access-specifier. ...

In class definitions, many times there are contiguous sequences of member declarations that have common specifiers. Under the proposal these common specifiers can be specified once at the start of a group of member declarations, rather than repeated for each member declaration. This can in some cases lead to cleaner, safer, easier-to-write, easier-to-read and easier-to-maintain code.

So instead of:

class foo : public bar
{
public:
    explicit foo(int);
    explicit foo(float);
    explicit foo(double);

protected:
    virtual T f() const override;
    virtual U g() const override;
    virtual V h() const override;
    virtual W i() const override;

private:
    static constexpr int X = 123;
    static constexpr float Y = 42.0f;
    static constexpr double Z = 123.0;
};

You could with group member specifiers equivalently write:

class foo : public bar
{
public explicit:
    foo(int);
    foo(float);
    foo(double);

protected virtual const override:
    T f();
    U g();
    V h();
    W i();

private static constexpr:
    int X = 123;
    float Y = 42.0f;
    double Z = 123.0;
};

N3928: Extending static_assert, v2 -- Walter Brown

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3928

Date: 2014-02-14

Extending static_assert, v2

by Walter Brown

Excerpt:

Following EWG guidance, this paper proposes wording to permit a default string literal for static_assert.

N3926: LWG Issue 2168 is NAD -- Walter Brown

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3926

Date: 2014-02-14

LWG Issue 2168 is NAD

by Walter Brown

Excerpt:

LWG issue 2168 reports a perceived inconsistency between two parts of the library’s specification for uniform_real_distribution. This paper argues that there is no inconsistency and that the issue should therefore be closed as NAD.

N3913: Greatest Common Divisor and Least Common Multiple, v2 -- Walter Brown

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3913

Date: 2014-02-25

Greatest Common Divisor and Least Common Multiple, v2

by Walter Brown

Excerpt:

This paper proposes two frequently-used classical numeric algorithms, gcd and lcm, for header <numeric>. The former calculates the greatest common divisor of two integer values, while the latter calculates their least common multiple. Both functions are already typically provided in behind-the-scenes support of the standard library’s <ratio> and <chrono> headers.

...

4 Acknowledgments

Many thanks to the readers of early drafts of this paper for their thoughtful comments. Special
thanks to Cassio Neri for his extra-careful proofreading and helpful suggestions.

N3911: TransformationTrait Alias void_t -- Walter Brown

A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3911

Date: 2014-02-23

TransformationTrait Alias void_t

by Walter Brown

Excerpt:

This paper proposes a new TransformationTrait alias, void_t, for the C++ Standard Library. The trait has previously been described as an implementation detail toward enhanced versions of two other C++11 standard library components. Its value thus proven, void_t’s standardization has been requested by several noted C++ library experts, among others.