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Explicit Is Better Than Implicit -- K-ballo

By Blog Staff | Jun 21, 2013 01:52 PM | Tags: intermediate explicit conversions basics

tales-of-cpp.PNGTales of C++, Episode 5:

Explicit Is Better Than Implicit

The Zen of Python tell us that Explicit is better than Implicit. This is good advice for any and all languages, but what are the implications in the C++ lands? There is one particular C++ feature that relates directly to that advice; one important enough that grants on its own the introduction of a keyword. That feature is user-defined conversions and that keyword is explicit.

C++ and Beyond 2013 is sold out

By Blog Staff | Jun 21, 2013 09:29 AM | Tags: None

cb13-soldout.pngAs interest in C++ continues to increase, not only are we seeing more C++ events, but they’re selling out quickly. This spring, both the Clang/LLVM developer conference and C++ Now 2013 (formerly BoostCon) were sold out long in advance.

Today, C++ and Beyond 2013 reported it has sold out nearly six months in advance. A waitlist is available.

If you missed registering for C++ and Beyond, check out additional C++ events coming up around the world in the Upcoming Events section on the sidebar. More major C++ events in Fall 2013 will be announced shortly...

Quick Q: Am I capturing a member variable by value? -- StackOverflow

By Blog Staff | Jun 19, 2013 03:35 PM | Tags: intermediate

Quick A: No. You're capturing "this" by value, which is a pointer, which effectively captures members by reference.

From StackOverflow:

Lambda captures and member variables

I was watching Herb Sutter's talk at the C++ and Beyond 2012 conference on Concurrency and he talks about creating a non-blocking wrapper class, which he calls concurrent<T>, with C++11 functions.

His implementation is fairly simple (aside from needing a concurrent_queue such as that which exists in Microsoft's PPL):

template <class T>
class concurrent {
private:
    mutable T t;
    mutable concurrent_queue<std::function<void()>> q;
    bool done = false;
    std::thread thread;

public:
    concurrent( T t_ = T{} ) : t{t_}, thread{ [=]{ while( !done ) q.pop()(); }} {}

    ~concurrent() { q.push( [=]{ done = true; } ); thread.join(); }

    template <typename F>
    void operator()( F f ) const { q.push( [=]{ f(t); } ); }

};

This seems simple enough, however, I'm confused as to why he has captured the member variables done and q by value instead of by reference? My understanding is that if they are captured by value then they will be copied to the thread and thus when the queue is updated the worker thread will not receive the updates?

Have I misunderstood how lambda captures work with regards to class member variables? No one said anything in the comments to the video or during the talk so I am assuming that my understanding is faulty, in which case could someone please clarify?

LLVM 3.3 is released!

By marshall | Jun 17, 2013 04:23 PM | Tags: None

You can download either the source or prebuilt executables from the LLVM web site

Clang 3.3 includes full C++11 support, as well as a suite of run-time checkers to help find bugs in your programs.

For more information, check out the release notes for LLVM and for Clang

Meeting C++ 2013 full schedule is available

By Blog Staff | Jun 17, 2013 10:41 AM | Tags: None

meeting-c++.PNGThe complete schedule has now been posted for the Meeting C++ conference to be held on November 8-9 in Düsseldorf, Germany.

The conference includes talks by ISO C++ standards committee members like Eric Niebler, Peter Sommearlad, Peter Gottschling, and more. Here are a just a few highlights:

  • Keynote: C++11 and No-Compromise Library Design (Eric Niebler)
  • Simpler Code through C++11 (Peter Sommerlad)
  • Scaling with C++11 (Edouard Alligand)
  • Modern C++ Network Programming (Glyn Matthews)
  • UI prototyping and development for multiple devices in C++ (John Thomas)
  • C++1y: Concepts Lite (Peter Sommerlad)

See the announcement for additional interesting talks.

 

C++11: The Future Is Here -- Bjarne Stroustrup

By Blog Staff | Jun 17, 2013 08:41 AM | Tags: None

stroustrup-accu2013.PNGStroustrup's ACCU keynote video is now available online.

C++11: The Future Is Here

Bjarne Stroustrup

Summary: Bjarne Stroustrup keynotes on what C++ is in general, how C++11 makes simple things even simpler, resource management, generic programming, and concurrency.

Regular Expressions 101: Regex in C++11 -- Brian Overland

By Blog Staff | Jun 14, 2013 04:43 PM | Tags: intermediate

overland_brian_c.jpgNew at InformIT:

Regular Expressions 101: Regex in C++11

by Brian Overland

From the article:

... You don't really need to know how it works. In fact, you only need to know a few things:

  • The regular expression grammar used by the C++11 regex library functions
  • The relevant C++11 functions and how to call them

The first part of this article focuses on the default regex grammar used in C++11: the ECMAScript grammar. You'll generally want to use ECMAScript, because it provides powerful capabilities while being easy to use. For simplicity, I'll focus on this grammar. ...

GotW #93 Solution: Auto Variables, Part 2 -- Herb Sutter

By Blog Staff | Jun 14, 2013 04:36 PM | Tags: intermediate basics

The solution to the latest GotW problem is now available:

GotW #93 Solution: Auto Variables, Part 2

by Herb Sutter

From the article:

As you worked through these cases, perhaps you noticed a pattern: The cases are mostly very different, but what they have in common is that they illustrate reason after reason motivating why (and how) to use auto to declare variables.

Let’s dig in and see...