New paper: N3702 Introducing an optional parameter for mem_fn -- Mikhail Semenov

By Blog Staff | Jul 2, 2013 10:02 AM | Tags: experimental

Note: This paper explores potential future standardization directions and alternatives. It does not discuss or propose to amend the C++14 Committee Draft paper whose ballot is currently in progress.

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: N3702

Date: 2013-06-28

Introducing an optional parameter for mem_fn, which allows to bind an object to its member function

by Mikhail Semenov

Excerpt:

When a member function is used as a parameter to another function (the latter is usually called a functional) it is often necessary to provide the corresponding class object as a parameter as well. But functionals, like for example an integral, are often written to accept one global function. In cases when a member function and an object are needed, it is necessary to bind them together,  so that the result can be supplied to the corresponding functional as one parameter. ...

... The proposal is to allow mem_fn to accept a second, optional parameter.

New paper: N3701, Concepts Lite (2nd revision) -- A. Sutton, B. Stroustrup, G. Dos Reis

By Blog Staff | Jul 2, 2013 09:56 AM | Tags: experimental

Note: This paper explores potential future standardization directions and alternatives. It does not discuss or propose to amend the C++14 Committee Draft paper whose ballot is currently in progress.

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: N3701

Date: 2013-06-28

Concepts Lite (2nd revision)

by A. Sutton, B. Stroustrup, G. Dos Reis

Excerpt:

This paper is in its 2nd revision. There have been a number of substantial
changes, which are summarize here.

• The syntax of constrained member functions has changed.
• The syntax of the requires expression has changed.
• We have introduced syntax for constraining generic lambdas, and using constraints wherever auto is used.
• We allow the use of overload sets as arguments to constrained functions.
• The standard wording has been more extensively developed, but does not yet include language for constrained generic lambdas.

This paper is organized like this:

• Tutorial: introduces the new features specified by Concepts Lite, their core concepts and examples.
• User’s guide: provides a more extensive discussion of the proposed features and demonstrates the completeness of the constraints mechanism. We also include some high-level discussion of the language mechanics.
• Discussion: explains what constrains are not. In particular, we try to outline constraint’s relation to concepts and to dispel some common misconceptions about concepts.
• Design Notes: Notes on the design of terse notation for templates and generic lambdas.
• Language definition: presents a semi-formal definition of constraints

New paper: N3700, Hierarchical Data Structures and Related Concepts -- B. Reiter, R. Rivera

By Blog Staff | Jul 2, 2013 09:50 AM | Tags: experimental

Note: This paper explores potential future standardization directions and alternatives. It does not discuss or propose to amend the C++14 Committee Draft paper whose ballot is currently in progress.

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: N3700

Date: 2013-06-22

Hierarchical Data Structures and Related Concepts for the C++ Standard Library

by B. Reiter, R. Rivera

Excerpt:

This paper proposes the addition of library components covering tree structures and related concepts to Programming Languages -- C++. The proposal is based on work towards a Boost Tree component library.

The library strives to cover many of the relevant aspects within the vast field linked to the notion of trees in computer science.

New paper: N3699, A proposal to add a generalized callable negator -- Tomasz Kamiński

By Blog Staff | Jul 2, 2013 09:45 AM | Tags: experimental

Note: This paper explores potential future standardization directions and alternatives. It does not discuss or propose to amend the C++14 Committee Draft paper whose ballot is currently in progress.

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: N3699

Date: 2013-05-27

A proposal to add a generalized callable negator

by Tomasz Kamiński

Excerpt:

The standard negators not1 and not2 accept only unary and binary functors that define argument_type or first_argument_type and second_argument_type respectively, which make them unusable with results of standard library functions such as bind and mem_fn. Furthermore, with relation to N3421, they cannot be used with new operator functor specializations.

This proposal addresses the problem by introducing a template function not_fn that returns complement of arbitrary predicate.

New paper: N3694, Feature-testing recommendations for C++ -- Clark Nelson

By Blog Staff | Jul 2, 2013 09:40 AM | Tags: experimental

Note: This paper explores potential future standardization directions and alternatives. It does not discuss or propose to amend the C++14 Committee Draft paper whose ballot is currently in progress.

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: N3694

Date: 2013-06-27

Feature-testing recommendations for C++

by Clark Nelson

Excerpt:

For the sake of improved portability between partial implementations of various C++ standards, WG21 (the ISO technical committee for the C++ programming language) recommends that implementers and programmers follow the guidelines in this document concerning feature-test macros.

Quick Q: Are there significant differences between boost::bind and std::bind? -- StackOverflow

By Blog Staff | Jul 1, 2013 01:58 PM | Tags: intermediate boost

A few minutes ago on SO:

Should I be seeing significant differences between std::bind and boost::bind?

I'm exploring the support for C++11 on the 4.7 branch of g++ (Ubuntu/Linaro 4.7.3-2ubuntu~12.04, to be specific) and I seem to be finding differences. In particular, if I comment out the #include of boost/bind.hpp and systematically replace occurrences of boost::bind with std::bind in the Boost ASIO async client example (taken from http://www.boost.org/doc/libs/1_45_0/doc/html/boost_asio/example/http/client/async_client.cpp), the program no longer compiles. Any explanation for this?

Boost 1.54.0 released!

By marshall | Jul 1, 2013 10:22 AM | Tags: intermediate boost advanced

Release 1.54.0 of the Boost C++ Libraries is now available.

These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications.
The Boost license encourages both commercial and non-commercial use.

This release contains five new libraries and numerous enhancements and bug fixes for existing libraries.

New Libraries:
Log: Logging library, from Andrey Semashev.
TTI: Type Traits Introspection library, from Edward Diener.
Type Erasure: Runtime polymorphism based on concepts.

For details, including download links, see http://www.boost.org/users/news/version_1.54.0

You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.54.0/

To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html

Thanks,

--The Boost release team

New paper: N3698, July 25-26 Santa Clara SG1 Meeting Announcement and Agenda -- Hans Boehm

By Blog Staff | Jun 30, 2013 08:22 PM | Tags: None

Note: This paper explores potential future standardization directions and alternatives. It does not discuss or propose to amend the C++14 Committee Draft paper whose ballot is currently in progress.

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: N3698

Date: 2013-06-30

July 25-26 Santa Clara SG1 Meeting Announcement and Agenda

by Hans Boehm

Excerpt:

Location

Nvidia, 2701 San Tomas Expressway, Santa Clara, CA. Meet at Building E lobby.

Agenda

2 Discuss parallellism and concurrency extensions for future C++ standards

2.1 Discuss previously submitted concurrency proposals that were insufficiently addressed at the Bristol meeting.

2.2 Discuss other proposals.