By Eric Niebler | Mar 1, 2013 01:36 PM | Tags: basics
Marshall Clow gives some helpful tips for C++ programmers migrating to to XCode 4.6:
C++ and XCode 4.6
So, you’ve installed Xcode 4.6, and you are a C++ programmer.
You want to use the latest and greatest, so you create a new project, and add your sources to the project, and hit Build, and … guess what? Your code doesn’t build!
By Blog Staff | Feb 28, 2013 08:19 AM | Tags: intermediate basics
We continue to see modern C++ tool development across the industry continue apace. Here's another new cool C++-oriented tool with a nice seven-minute video on Channel 9:
Introducing Image Watch - A VS 2012 Plug-In for C++ Image and Video Debugging
Image Watch is a new Visual Studio 2012 plug-in for debugging C++ image and video processing applications, for example photo or augmented reality apps. Image Watch provides a watch window that can display in-memory bitmaps during debugging, so you no longer need to litter your code with "save-this-intermediate-image-to-a-file" statements when tracking down bugs. The initial release has built-in support for OpenCV image types and can be extended for viewing user-defined image types as well.
Here, Wolf Kienzle, Senior Research Developer, Interactive Visual Media group, Microsoft Research Redmond, explains and demos this excellent new tool for C++ developers building image, video or augmented reality apps. In effect, you can step into pixels...
By Blog Staff | Feb 25, 2013 08:55 AM | Tags: basics
People new to C++11 often hear about move semantics, and expect that they have to do work to take advantage of it. That's often not true, and often the cleanest, simplest code that doesn't even mention move or && anywhere is just what you want -- that's C++11, clean, safe, and faster than ever.
Perhaps the most common case (and question) involves returning values from functions. The new rule for modern C++ style: Just return even big objects by value, and move Just Happens.
It just came up again on StackOverflow:
C++11 rvalues and move semantics confusion
The link skips straight to Howard Hinnant's clear and correct answer.
Sometimes we just try too hard, because we expect efficient programming not to be easy. Welcome to C++11.
By Blog Staff | Feb 19, 2013 04:39 AM | Tags: basics
Quick A: Using the form of insert that takes an rvalue and passing a temporary or a std::move'd object, or calling emplace.
Moving an object into a map
The problem with this is that the huge objects will be copied into the maps
Huge huge1(some,args); Huge huge2(some,args); std::map<int,Huge> map1; std::map<Huge,int> map2; map1.insert({0,huge1}); map2.insert({huge2,0});how can I guarantee a move? Will this work or is there more to it?
map1.insert({0,std::move(huge1)}); map2.insert({std::move(huge2),0});
By Blog Staff | Feb 18, 2013 05:32 PM | Tags: intermediate basics
Quick A: Yes. Another way that modern C++ is safer and simpler.
(If you don't know what the safe-bool idiom is, don't worry. It's a workaround that's now obsolete.)
Xeo asked:
Is the safe-bool idiom obsolete in C++11?
This answer of @R. Martinho Fernandes shows, that the safe-bool idiom is apperently deprecated in C++11, as it can be replaced by a simple
explicit operator bool() const;... Is our assumption in the title correct? I hope we didn't overlook any potential drawbacks.
By Blog Staff | Feb 15, 2013 10:38 AM | Tags: intermediate basics
Andrzej continues this month with more interesting thoughts on preconditions.
Preconditions, Part 2
by Andrzej Krzemieński
In this post I will continue sharing my thoughts on preconditions. It will cover some philosophy behind the concept of preconditions (and bugs), and investigate the possibility of employing the compiler to verify some preconditions. Many people provided a useful feedback on my previous post. I will also try to incorporate it into this post.
Note that this article diverges from recommended practice in one way... it hints at the idea of throwing exceptions to report precondition violations. Instead, per C++ Coding Standards and other established guidance, prefer to use assertions to check preconditions: precondition violations are just bugs in the caller's code that should be caught at test time, assertions cause no overhead in production, and assertions fire immediately at the line of code that contains the bug without losing the call stack and other local context. Using assertions is still considered to be a best practice.
By Blog Staff | Feb 14, 2013 09:39 AM | Tags: basics
Now at InfoQ:
Learning Modern C++: An Interview with Barbara Moo
by Jeff Martin
The popularity of C++ has varied throughout the years since its introduction in the 1980s. The rise of managed languages like Java and C# along with the emergence of scripting languages like JavaScript, Python, and Ruby has affected C++'s adoption. Yet many supporters like C++ for the control, raw power, and speed that it offers. C++11 promises to bring that power to programmers in a more efficient manner, and the changes it introduces illustrate how much the language has grown in the past 30 years. Programmers looking to learn about C++11 or perhaps sample C++ for the first time would do well to try C++ Primer, 5th Edition by Stanley B. Lippman, Josée Lajoie, and Barbara E. Moo. InfoQ had the opportunity to speak with Ms. Moo about her new book and the C++ language as a whole.
By don_tait | Feb 12, 2013 01:31 PM | Tags: intermediate basics
KDAB is now offering three-day training courses in C++11.
What’s New in C++11?
This three-day training teaches everything about the new C++ standard, C++11.
C++11 will become more and more important in the C++ ecosystem, eventually becoming the most prevalent version. Every professional developer should invest in learning the new language version and try introducing its benefits into projects. And for good reasons: C++11 brings a large range of new features that makes development safer, faster, easier and more fun. Once you have tried features like lambda functions, range-based for loops, the auto keyword and the new initialization syntax, you won't want to go back. In addition to that, many more advanced features like variadic templates, rvalue reference and of course the new standard library additions like multithreading classes, smart pointers, regular expressions and new containers and algorithms complete the picture.
During the training day at Qt DevDays 2012 in Berlin, KDAB engineer Marc Mutz, presented some the most important C++11 features using parts of the material from this course. This was very well attended, receiving positive feedback.
Our full training lasts for three days and covers a wide range of topics, it goes in-depth and provides time to show C++11 examples as well as allowing participants to go hands-on and trying out C++11 themselves in exercise projects.
See the course description for more details about the content.
To view our schedule and to book your place for our next C++11 trainings go to: www.kdab.com/schedule/
By Blog Staff | Feb 11, 2013 10:41 AM | Tags: intermediate basics advanced
The final dates and location are now set for C++ and Beyond 2013 with Scott Meyers, Herb Sutter, and Andrei Alexandrescu:
December 9-12, 2013 in beautiful Snoqualmie, Washington, USA.
From Scott Meyers' announcement:
About a month ago, I posted tentative dates for C&B 2013. I cautioned that there was no contract yet, and I’m glad I did, because shortly thereafter we discovered an off-by-one scheduling snafu. As a result, the dates are not the ones I posted earlier, they’re a day later: Monday evening, December 9, through Thursday, December 12.The inital C&B in 2010 was held at the Salish Lodge and Spa in Snoqualmie, Washington, USA. In 2011, we had a larger group in a larger venue, and last year we bumped up the numbers again. Growth was ours, it seemed, but we sensed that C&B was looking more like a conventional conference and less like the unique event we had originally envisioned. For 2013, we decided to return to our roots, both geographically and organizationally.
C&B 2013 will return to the Salish Lodge and Spa in Snoqualmie, Washington (not far from Seattle). Enrollment will again be limited to the capacity of the ballroom (~64 attendees). Scott will again lead lunchtime walks. Evenings will again feature free-form “hang out with the speakers” sessions. Hotel guestrooms will again boast fireplaces, whirlpool tubs for two, and one whopping big waterfall just steps from the front door. If you were part of C&B 2010, you know what I’m talking about. If you weren’t, ask around: you’ll wish you had been.
We’ll announce more details when they’ve been finalized, including when registration for C&B 2013 will begin. In the meantime, reserve December 9-12 for C++ and Beyond 2013 in Snoqualmie, Washington, USA.
By Blog Staff | Feb 8, 2013 09:36 AM | Tags: basics
The final installment of Bjarne Stroustrup's four-part Tour of C++ is now available. This material is a preview draft of Chapter 5 of Stroustrup’s upcoming The C++ Programming Language, 4th Edition.
A Tour of C++, Part 4: Concurrency and Utilities
by Bjarne Stroustrup
Bjarne writes:
Describe all of C++ in 100 pages (or less). Don't just describe the language, include the standard library. Don't use "white lies" to simplify. Describe the major programming styles and techniques. Give rationale. Don't forget about concurrency. And, oh, by the way, make it readable to programmers (do not require a PhD).
That was the task I set myself when I decided to write the "Tour of C++" for TC++PL4. I suspect that succeeding perfectly is beyond me, but at least I met the first criteria: The tour is currently 98 pages, and shrinking.
This last, part 4, of the tour presents concurrency and some of the newer standard-library facilities.Enjoy!
See the whole Tour here.