March 2014

C++11/14 Standard & Standardization--Peter Sommerlad

Peter Sommerlad on C++11 and C++14 Standard(s) and Standardization:

Peter Sommerlad on C++11 and C++14 Standard(s) and Standardization

Created by Peter Sommerlad March 6, 2014

From the presentation:

Why is C++ in again?

• more computing per Watt!
  • mobile - battery powered
  • servers - cloud computing
  • high-performance computing & GPUs
• better abstractions than C
  • without performance price (e.g. of a VM)
  • embedded (higher-level type safety)
  • security (buffer overruns, pointers)

Slides (PDF)

Effective Modern C++ book status -- Scott Meyers

Scott Meyers' work on his new "Effective C++" book, tentatively titled Effective Modern C++, progresses with an updated draft table of contents and sample Item available:

Book Report: New Title, New TOC, New Sample Item

by Scott Meyers

Highlights from the article:

I recently finished the 32nd Item for the book, thus giving me drafts of five full chapters. The math still shows that about 40 Items will fit in the book's allotted 300 pages, so yesterday I took a hatchet to the prospective table of contents and chopped the number of Items down from 51 to 41. (Why 41? Because I have a feeling that one of the Items I've written will eventually get jettisoned as not being important enough to make the final cut.)  Here's the current draft TOC....

[Table of Contents -- read it, just the titles give useful guidance]

... The most recent Item I wrote was "Distinguish () and {} when creating objects." I blogged about one aspect of this topic here, and I thought you might be interested to see what I came up with. I've therefore made the current draft of this Item available, and I welcome your comments on it. Like almost all Items I've written, it's too long, so I'm especially interested in suggestions on how I can make it shorter, but I welcome all suggestions for improvement.

Upcoming Public Presentations by Scott Meyers

Scott Meyers has announced upcoming talks for 2014:

Upcoming Public Presentations

by Scott Meyers

2014 is shaping up to be a year with more public presentations than usual. As always, you can find links to all my scheduled talks at my Upcoming Talks page, but here are the ones scheduled so far: ... there will be more to come.

Highlights from the article:

May 22, Menlo Park, CA, USA: "The Last Thing D Needs"

June 4, Oslo, Norway: "Effective Modern C++," "Type Deduction and Why You Care," "The Most Important Design Guideline," and "CPU Caches and Why You Care"

September 17, Pennsylvania, USA: "CPU Caches and Why You Care"

October 7-8, London, UK: Two-day "Effective C++11/14 Programming" seminar

String's Length -- Andrzej KrzemieĊ„ski

Today from the desk of Andrzej:

String's Length

by Andrzej Krzemieński

From the article:

Let’s start with a small test. Is the invariant expressed with the following assertion correct?

void test_length(std::string const& s)
  assert(s.length() == strlen(s.c_str()));

It is not; otherwise I wouldn’t be mentioning this in the post; but do you know why it is wrong? ...

CppCon 2014 Registration Open: September 7-12, Bellevue, WA, USA

cppcon-173.PNGThe Standard C++ Foundation is very pleased to announce the first annual CppCon.


Registration is now open for CppCon 2014 to be held September 7–12, 2014 at the Meydenbauer Center in Bellevue, Washington, USA. The conference will start with the keynote by Bjarne Stroustrup titled "Make Simple Tasks Simple!"

CppCon is the annual, week-long face-to-face gathering for all C++ users. The conference is organized by the C++ community for the community. You will enjoy inspirational talks and a friendly atmosphere designed to help attendees learn from each other, meet interesting people, and generally have a stimulating experience. Taking place this year in the beautiful Seattle neighborhood and including multiple diverse tracks, the conference will appeal to anyone from C++ novices to experts.

What you can expect at CppCon:

  • Invited talks and panels: The CppCon keynote by Bjarne Stroustrup will start off a week full of insight from some of the world’s leading experts in C++. Still have questions? Ask them at one of CppCon’s panels featuring those at the cutting edge of the language.
  • Presentations by the C++ community: What do embedded systems, game development, high frequency trading, and particle accelerators have in common? C++, of course! Expect talks from a broad range of domains focused on practical C++ techniques, libraries, and tools.
  • Lightning talks: Get informed at a fast pace during special sessions of short, less formal talks. Never presented at a conference before? This is your chance to share your thoughts on a C++-related topic in an informal setting.
  • Evening events and “unconference” time: Relax, socialize, or start an impromptu coding session.

CppCon’s goal is to encourage the best use of C++. The conference is a project of the Standard C++ Foundation, a not-for-profit organization whose purpose is to support the C++ software developer community and promote the understanding and use of modern, standard C++ on all compilers and platforms.

Looking at C++14

A few weeks ago the C++ committee did meet in Issaquah, its most important result: the final draft for C++14. See Herb Sutters trip report for details, I have written an overview based on his trip report, clangs C++14 status page and of course the papers it self.

Looking at C++14

by Jens Weller

From the Article:

As I have read through most papers of last and this year, a short overview which papers now have made it into the standard. So, what are the new features of C++14? Already before the last meeting, clang had implemented all known C++14 features of the draft published after the Chicago meeting.

Quick Q: When should you prefer std::function vs. a virtual function to implement a callback? -- SO

Quick A: Using a named abstract base class makes code more tightly coupled to that specific name. Where possible, prefer using std::function which is more general and flexible.

Recently on SO:

Pros & cons of a callback (std::function/std::bind) vs an interface (abstract class)

I'm creating a server application in C++11 using Boost.Asio. I've created a class, Server, which takes care of accepting new connections. It's basically just:

void Server::Accept() {
  socket_.reset(new boost::asio::ip::tcp::socket(*io_service_));
                         boost::bind(&Server::HandleAccept, this, boost::asio::placeholders::error));
void Server::HandleAccept(const boost::system::error_code& error) {
  if (!error) {
    // TODO
  } else {
    TRACE_ERROR("Server::HandleAccept: Error!");

I've found two ways (I'm sure there are more) to "fix" the TODO comment, i.e. to move the socket to wherever it should go. In my case I just want it back to the class instance that owns the Server instance (which then wraps it in a Connection class and inserts it to a list).

  1. Server has a parameter in its constructor: std::function<void(socket)> OnAccept which is called in HandleAccept.
  2. I create an abstract class, IServerHandler or whatever, which has one virtual method OnAccept. Server takes IServerHandler as parameter in its constructor and the class instance owning the server instance extends IServerHandler and constructs Server with *this as parameter.

What are the pros and cons of option 1 vs option 2? Are there any better options? I'm having the same problem in my Connection class (OnConnectionClosed). Also, depending on how I decide to design the system, it might need a OnPacketReceived and OnPacketSent callback.

Stroustrup & Sutter on C++ Update

eelive.PNGUpdate: The EE Live! organizers have announced that they are able to expand the room for Stroustrup & Sutter on C++, and so seats are still available for Bjarne Stroustrup's and Herb Sutter's two-day seminar:

Super C++ Tutorial: Stroustrup & Sutter on C++

EE Live!
March 31 - April 1, 2014
McEnery Convention Center
San Jose, CA, USA

We invite you to spend two insightful and informative days with C++ luminaries Bjarne Stroustrup, the creator of C++, and Herb Sutter, the chair of the ISO C++ committee, as they address the most important issues for C++ developers in 2014.

If you are interested in attending and have not registered yet, seats are still available -- register today.

See also the session details announcement for more information about topics and content. This event is especially well timed with the technical completion of C++14 just one month ago, and will include solid and practical coverage from two of the key people who shape the C++ standard about how to effectively apply many C++14 features that are already available in your current compilers.

Fun with Lambdas: C++14 Style (Part 1) -- Sumant Tambe

sumant-tambe.PNGA rapid-fire "now write this using lambdas" problem-solution drill with Sumant Tambe:

Fun with Lambdas: C++14 Style (Part 1)

by Sumant Tambe

From the article:

It's common knowledge that Functional Programming is spreading like a wildfire in mainstream languages. Latest promoted languages: Java 8 and C++, both of which now support lambdas. So, let the lambdas begin! and may the fun be ever on your side. The same text is available in slides form on Slideshare. This blog post and the talk/slides are inspired by JSON inventor Douglas Crockford.

C++: The Good Parts -- Jordan DeLong

delong.PNGA fun(ctional) talk from QCon:

C++: The Good Parts (slides)

by Jordan DeLong

The talk abstract:

Although C++ originated with the primary aim of adding Object Oriented features to C, it has evolved from the OO paradigm into a multi-paradigm language with strong support for various functional programming idioms.   C++11 adds several language features, most notably lambda expressions, that are overtly functional. But even prior to C++11, key parts of the standard library sported a design that has fundamentally more in common with functional programming than with OO.   This talk gives an overview of the past, current and near future "good parts" of C++'s functional side, through the colored lens of the speaker's biases.