The CppCon 2015 conference program has been posted for the upcoming September conference. We’ve received requests that the program continue to be posted in “bite-sized” posts, a few sessions at a time, to make the 100+ sessions easier to absorb, so here is another set of talks. This series of posts will conclude once the entire conference program has been posted in this way.

The following interrelated CppCon 2015 talks tackle interesting issues and more.

In this post:

• An Overview on Encryption in C++
• Demystifying Floating Point Numbers
• What is Open Source, and Why Should You Care?
• Live lock-free or deadlock (practical Lock-free programming), Part I, and Part II
• Programming with less effort in C++
• Functional Design Explained

An Overview on Encryption in C++ by Jens Weller, Meeting C++, Meeting C++

Encryption has become a very important topic for C++ developers and this session will serve as an introduction and overview this topic. I will present an overview on the popular encryption libraries cryptopp, botan and libsodium, and give you an update on the popular encryption algorithms of AES and RSA, plus why cryptoboxes can be a great help.

Demystifying Floating Point Numbers by John Farrier, Sr. Lead Technologist, Booz Allen Hamilton

Every day we develop software that relies on math while we often overlook the importance of understanding the implications of using our IEEE floats. From the often cited “floating point error” to unstable algorithms, this talk will explain the importance of floats, understanding their storage, the impact of the IEEE floats on math, and designing algorithms better. Finally, the talk will conclude with a quick case study of storing time for games and simulations.

What is Open Source, and Why Should You Care? by Kevin P. Fleming, Member of the CTO Office, Bloomberg

In this session, Kevin will present a condensed history of open source software: its origins, motivations and effect on the world of software development. He'll then talk about open source *beyond* software, and various ways that students can get involved in open source projects to develop useful (and marketable) skills. These are skills which are not taught in most degree programs, but are very valuable for jobs in scientific and engineering disciplines.

Live lock-free or deadlock (practical Lock-free programming), Part I, and Part II by Fedor Pikus, Chief Scientist, Mentor Graphics

Part I: Introduction to lock-free programming. We will cover the fundamentals of lock-free vs lock-based programming, explore the reasons to write lock-free programs as well as the reasons not to. We will learn, or be reminded, of the basic tools of lock-free programming and consider few simple examples. To make sure you stay on for part II, we will try something beyond the simple examples, for example, a lock-free list, just to see how insanely complex the problems can get.

Part II: having been burned on the complexities of generic lock-free algorithms in part I, we take a more practical approach: assuming we are not all writing STL, what limitations can we really live with? Turns out that there are some inherent limitations imposed by the nature of the concurrent problem: is here really such a thing as “concurrent queue” (yes, sort of) and we can take advantages of these limitations (what an idea, concurrency actually makes something easier!) Then there are practical limitations that most application programmers can accept: is there really such a thing as a “lock-free queue” (may be, and you don’t need it). We will explore practical examples of (mostly) lock-free data structures, with actual implementations and performance measurements. Even if the specific limitations and simplifying assumptions used in this talk do not apply to your problem, the main idea to take away is how to find such assumptions and take advantage of them, because, chances are, you can use lock-free techniques and write code that works for you and is much simpler than what you learned before.

Programming with less effort in C++ by Ferreira Da Costa and Sylvain JUBERTIE

The C++ language and libraries propose different ways to implement codes. For example, using explicit loops or STL algorithms to traverse containers and process data. C++11&14 bring also new features to the C++ language aimed at simplifying the writing of codes. But what is the gain we can expect in term of development effort when using these different possibilities and features ? or, as a developer may ask himself: Is it viable for me to spend some time learning new C++ libraries or standards to provide less effort/spend less time on my future codes ?

Before answering these questions, we must give a definition of the development effort, and define a way to measure it. Thus, we first propose to describe existing software metrics, from the simple Single Line Of Code (SLOC) to the more complex Halstead metrics, then to implement them in an automatic tool based on Clang tools, and finally to apply them on several codes to compare their respective development efforts.

First results show that using modern C++ features like auto, decltype and lambdas help to dramatically reduce the development effort. These results may help to convince developers to use new C++ features, or to port their codes from old standards to new ones, or even switch from other languages to C++ !

Functional Design Explained by David Sankel, Untitled, Stellar Science

An oft-cited benefit of learning a functional language is that it changes one's approach to solving problems for the better. The functional approach has such a strict emphasis on simplistic and highly composable solutions that an otherwise varied landscape of solution possibilities narrows down to only a few novel options.

This talk introduces functional design and showcases its application to several real-world problems. It will briefly cover denotational semantics and several math-based programming abstractions. Finally, the talk will conclude with a comparison of functional solutions to the results more traditional design methodologies.

No prior knowledge of functional programming or functional programming languages is required for this talk. All the examples make use of the C++ programming language.