October 25, Pavia, Italy
November 6-8, Berlin, Germany
November 3-8, Kona, HI, USA
By Meeting C++ | Oct 10, 2013 07:52 AM | Tags: community
A short overview over the upcoming C++ User Group Meetings in October:
C++ User Group Meetings in October
by Jens Weller
From the Article:
Also in October a lot of C++ User Groups are meeting again. For Europe its 6 User Groups meetings, with a new one in Wroclaw, Poland!
By hendrixjl | Oct 10, 2013 06:28 AM | Tags: performance intermediate efficiency concurrency
Jeff Preshing gives a nice overview of the on-again/off-again/on-again status of a common approach to lazy initialization.
[Ed: Note that DCLP is not just for thread-safe singletons, that's just a handy example. It's for lazy initialization in general.]
Double-Checked Locking Is Fixed in C++11
by Jeff Preshing
From the article:
The double-checked locking pattern (DCLP) is a bit of a notorious case study in lock-free programming. Up until 2004, there was no safe way to implement it in Java. Before C++11, there was no safe way to implement it in portable C++.
As the pattern gained attention for the shortcomings it exposed in those languages, people began to write about it. In 2000, a group of high-profile Java developers got together and signed a declaration entitled “Double-Checked Locking Is Broken”. In 2004, Scott Meyers and Andrei Alexandrescu published an article entitled “C++ and the Perils of Double-Checked Locking”. Both papers are great primers on what DCLP is, and why, at the time, those languages were inadequate for implementing it.
All of that’s in the past. Java now has a revised memory model, with new semantics for the volatile keyword, which makes it possible to implement DCLP safely. Likewise, C++11 has a shiny new memory model and atomic library which enable a wide variety of portable DCLP implementations. C++11, in turn, inspired Mintomic, a small library I released earlier this year which makes it possible to implement DCLP on some older C/C++ compilers as well.
In this post, I’ll focus on the C++ implementations of DCLP...
By Blog Staff | Oct 9, 2013 03:11 PM | Tags: None
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: N3804
Date: 2013-10-09
Any Library Proposal (Revision 3)
by Beman Dawes, Kevlin Henney, Daniel Krügler
Excerpt:
This paper proposes a type-safe container for single values of value types. The C++ standards committee is planning to include the proposal in a library Technical Specification (TS).
The proposal is based on the Boost Any Library (see www.boost.org/libs/any). The Boost version of library has been in wide use for over a decade, and the library has been implemented at least twice in addition to the Boost implementation. The proposal is a pure addition to the standard library, requires no modifications to any C++14 standard library components, requires no compiler support, and will have no effect on existing namespace-disciplined code.
By Blog Staff | Oct 9, 2013 01:35 PM | Tags: None
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: N3803
Date: 2013-10-05
File System Technical Specification (PDTS)
by Beman Dawes
Excerpt:
This Technical Specification specifies requirements for implementations of an interface that computer programs written in the C++ programming language may use to perform operations on file systems and their components, such as paths, regular files, and directories. This Technical Specification is applicable to information technology systems that can access hierarchical file systems, such as those with operating systems that conform to the POSIX ([fs.norm.ref]) interface. This Technical Specification is applicable only to vendors who wish to provide the interface it describes.
By Blog Staff | Oct 9, 2013 12:06 PM | Tags: None
Ready for a full day of C++11/14/17 content in the Spanish language?
using std:cpp
November 26, 2013
University Carlos III of Madrid in Leganés
The site and the event are entirely in Spanish. For convenience, here is an automatic translation of the event page:
Welcome to using std::cpp 2013
using std::cpp 2013 aims to be a forum for exchanging experiences using the C++ language, paying special attention to the recent standard C++11 and the upcoming C++14 and C++17.
Who should attend using std::cpp 2013?
The event is aimed at professional developers using C++ as a language for application development or infrastructure software. It is also aimed at students of last years of career, interested in the use of C++ as a programming language to produce complex computer systems with high performance.
What can I find in using std:cpp 2013?
We have prepared an intensive programme with presentations by leading developers from leading companies in their sectors (Indizen, TCP-SI, BBVA, Telefónica, Digital, INDRA, Biicode, Microsoft, Programming Research Group).
You can refer to the detailed program to see topics you can expect.
When does using std::cpp take place?
using std::cpp 2013 will be held on November 26, 2013 at the School Politécnica Superior of the Universidad Carlos III de Madrid in Leganes and will last for a full day.
Do I need to register?
using std::cpp 2013 attendance is free, but you must register to facilitate the organization of the event. You can register here.
By Blog Staff | Oct 9, 2013 11:15 AM | Tags: basics
The question, rephrased: Does =delete mean "make the compiler skip this function and keep looking," or "make this function unusable and make the caller fix their code" -- and why?
What's the exact semantics of a deleted function in C++11?
struct A { A(); A(const A&); A& operator =(const A&); A(A&&) = delete; A& operator =(A&&) = delete; }; struct B { B(); B(const B&); B& operator =(const B&); }; int main() { A a; a = A(); // error C2280 B b; b = B(); // OK }My compiler is VC++ 2013 RC.
error C2280: 'A &A::operator =(A &&)' : attempting to reference a deleted functionI just wonder why the compiler doesn't try
A& operator =(const A&);whenA& operator =(A&&)is deleted?Is this behavior defined by the C++ standard?
By Blog Staff | Oct 9, 2013 08:54 AM | Tags: intermediate boost
Speaking of ACCU 2014, here's an excellent talk from ACCU 2013 showing how C++11 (by itself, and/or with Boost) makes expressing many common design patterns far simpler than using traditional pre-C++11 tools. In fat, are there cases where the design patterns even disappear entirely? Watch to find out.
Effective GoF Patterns with C++11 and Boost (slides)
by Tobias Darm
Abstract and bio:
Tobias Darm discusses how some of the GoF patterns can be implemented differently in C++11 using Boost libraries.
Tobias Darm is working with C++ and programming embedded devices used in an intensive care environment at Dräger medical. He likes to learn and teach about software development and does tutorials and workshops in his company encouraging a modern programming style.
By Blog Staff | Oct 8, 2013 03:23 PM | Tags: None
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: N3802
Date: 2013-10-08
apply() call a function with arguments from a tuple
by Peter Sommerlad
Excerpt:
Tuples are great for generic programming with variadic templates. However, the standard does not define a general purpose facility that allows to call a function/functor/lambda with the
tupleelements as arguments. ...
By Blog Staff | Oct 8, 2013 03:13 PM | Tags: None
Preparations are underway for the ACCU 2014 conference, to be held April 8-12, 2014 somewhere in the U.K. The conference has historically had strong C++ representation, and this year features a keynote by Howard Hinnant, longtime ISO C++ participant and former Library Working Group chair, and now a principal developer on Clang's libc++ implementation of the ISO C++ standard library. It also includes sessions on other languages and environments besides C++.
The conference has issued a call for papers which will close on Monday, November 5. From the call:
We have a long tradition of high quality sessions covering many aspects of software development, from programming languages (e.g., Java, Javascript, C#, Clojure, Python, Erlang, Haskell, Ruby, Groovy, C, C++, etc.), and technologies (libraries, frameworks, databases, etc.) to subjects about the wider development environment such as testing, architecture and design, development process, analysis, patterns, project management, and softer aspects such as team building, communication and leadership.
Sessions are usually tutorial-based, presentations of case studies, or interactive workshops, but we are always open to novel formats.
Pre-conference workshops are all day. Main conference sessions are 90 minutes. There are also a few 45 minutes sessions (reserved for less experienced speakers).
[...]
The Call for Papers lasts 5 weeks and will close on Monday 5th November 2013. Remember, remember, the 5th of November...
Full conference schedule will be announced 1st Jan 2014.
See the call for details on how to submit a proposed session.
By Blog Staff | Oct 4, 2013 10:06 AM | Tags: None
Bjarne Stroustrup will be giving his "The Essence of C++" talk live in person next week at the UNT College of Engineering near Dallas, TX, USA.
The Essence of C++
by Bjarne Stroustrup
Location: UNC College of Engineering (map)
Friday, October 11, 2013
Talk: 2:00 p.m. –- 3:30 p.m.
Reception: 3:30 -- 4:00 p.m.
Abstract
C++11 is being deployed and the shape of C++14 is becoming clear. This talk examines the foundations of C++. What is essential? What sets C++ apart from other languages? How does new and old features support (or distract from) design and programming relying on this essence.
I focus on the abstraction mechanisms (as opposed to the mapping to the machine): Classes and templates. Fundamentally, if you understand
vector, you understand C++.Type safety and resource safety are key design aims for a program. These aims must be met without limiting the range of applications and without imposing significant run-time or space overheads. I address issues of resource management (garbage collection is not an ideal answer and pointers should not be used as resource handles), generic programming (we must make it simpler and safer), compile-time computation (how and when?), and type safety (casts belongs in the lowest-level hardware interface). I will touch upon move semantics, exceptions, concepts, type aliases, and more. My aim is not so much to present novel features and technique, but to explore how C++’s feature set supports a new and more effective design and programming style.