CppCon 2019: C++ Code Smells--Jason Turner

By Adrien Hamelin | Aug 19, 2020 02:24 PM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

C++ Code Smells

by Jason Turner

Summary of the talk:

There are a lot of rules to remember for writing good C++. Which features to use? Which to avoid? The C++ Core Guidelines would be over 500 pages long if you were to try to print it! What happens if we swap this around and instead of Best Practices look at Code Smells. Coding decisions that should make you think twice and reconsider what you are doing.

We will ask:

* What are the most important code smells?
* Does it simplify the way we write code?

CopperSpice: Time Complexity

By Ansel Sermersheim | Aug 18, 2020 11:54 AM | Tags: None

New video on the CopperSpice YouTube Channel:

Time Complexity

by Barbara Geller and Ansel Sermersheim

About the video:

In this video we investigate the topic of time complexity, explain a little of the mathematical background, and show its practical applications to C++ programming. We talk about some of the common time complexity notations, and which algorithms you should choose based on their time complexity properties.

Please take a look and remember to subscribe!

CppCon 2019: Writing Safety Critical Automotive C++ Software for AI Hardware--Michael Wong

By Adrien Hamelin | Aug 17, 2020 11:15 AM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

Writing Safety Critical Automotive C++ Software for High Performance AI Hardware

by Michael Wong

Summary of the talk:

How can we make C++ in a Safe and secure way?
It is about time we talk about what it takes to create safe software, especially for automotive. This talk is about the practical engineering challenges of turning deep learning, classical machine vision and sensor fusion algorithms from research prototypes into real-world automotive-grade systems. We will summarize the many safety critical standards in general for C++ and specifically for autonomous vehicles (AV). These include the updates to MISRA, AUTOSAR, and our own SG12 which has been processing updates from WG23 for C++. We have been working hard in these standards bodies and with industrial partners to deliver automotive-grade, safe, high performance AI software development tools.
We will further review C++ Directions that supports this and reveal the road map for what is possibly the earliest Safety Critical C++ that is also capable of heterogeneous dispatch for AV.

C++ Weekly - Ep 231 - Multiple Destructors in C++20?! How and Why--Jason Turner

By Adrien Hamelin | Aug 17, 2020 11:10 AM | Tags: c++20

Curious but useful?

C++ Weekly - Ep 231 - Multiple Destructors in C++20?! How and Why

by Jason Turner

CppCon 2019: Floating-Point ＜charconv＞: Making Your Code 10x Faster With C++17's Final Boss--STL

By Adrien Hamelin | Aug 14, 2020 01:01 PM | Tags: performance community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

Floating-Point ＜charconv＞: Making Your Code 10x Faster With C++17's Final Boss

by Stephan T. Lavavej

Summary of the talk:

Floating-point numbers are ancient, mysterious, and terrifying. Over the past 30 years, the C and C++ Standards have provided many functions for floating-point/string conversions, such as C's strtof(), strtod(), and printf() %a %e %f %g, and C++'s iostreams, stof(), stod(), and to_string(). Despite this history, floating-point is far from a solved problem - these functions have ranged from annoyingly to egregiously slow, and application developers and library maintainers alike have found it exceedingly difficult to understand floating-point behavior.

This session will present new and wondrous developments in the area of floating-point conversions. If your serialization code is bottlenecked by floating-point printing, this will accelerate your code by roughly 3x to 30x (yes, times, not percent). You can also improve the human-readability of your output. Along the way, this session will cover the basics of floating-point representations, dispelling common myths like fuzziness and non-determinism.

Specifically, C++17 added 3 pages of Standardese describing the charconv header and its functions from_chars() and to_chars(). This feature has required an unexpectedly large amount of implementation work, taking over a dev-year for MSVC and becoming the last C++17 library feature to ship. Coincidentally, Ulf Adams at Google developed a novel algorithm named Ryu, which is responsible for the amazing speed of to_chars(). This session will focus on how to use charconv and how to understand its many supported formats, with a brief overview of Ryu's techniques.

CppCon 2019: Mesh: Automatically Compacting Your C++ Application's Memory--Emery Berger

By Adrien Hamelin | Aug 12, 2020 11:12 AM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

Mesh: Automatically Compacting Your C++ Application's Memory

by Emery Berger

Summary of the talk:

Programs written in C++ can suffer from serious memory fragmentation, leading to low utilization of memory, degraded performance, and application failure due to memory exhaustion. This talk introduces Mesh, a plug-in replacement for malloc that, for the first time, eliminates fragmentation in unmodified C++ applications through compaction. A key challenge is that, unlike in garbage-collected environments, the addresses of allocated objects in C++ are directly exposed to programmers, and applications may do things like stash addresses in integers, and store flags in the low bits of aligned addresses. This hostile environment makes it impossible to safely relocate objects, as the runtime cannot precisely locate and update pointers. Mesh combines novel randomized algorithms with widely-supported virtual memory operations to provably reduce fragmentation, breaking long-established worst-case bounds on memory efficiency with high probability. Mesh generally matches the runtime performance of state-of-the art memory allocators while reducing memory consumption and eliminating pathological cases; in particular, Mesh reduces the memory of consumption of Firefox by 16% and Redis by 39%. There are efforts underway to incorporate Mesh's approach to eliminate fragmentation into existing allocators like tcmalloc and jemalloc; Mesh itself is available at https://github.com/plasma-umass/Mesh, and it can be used just by setting an environment variable.

CppCon 2019: C++20: The small things--Timur Doumler

By Adrien Hamelin | Aug 10, 2020 11:58 AM | Tags: community c++20

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

C++20: The small things

by Timur Doumler

Summary of the talk:

C++20 comes with some big new language features: modules, coroutines, concepts, spaceship, and many new libraries. But apart from all those, C++20 also offers many small language improvements, making C++ more powerful and expressive, but also safer and more consistent.

This talk is an overview over all those smaller additions to the core language that will make your life easier. We will discuss much-needed improvements to existing facilities such as lambdas, CTAD, structured bindings, and initialisation, as well as brand-new language utilities that you may not yet have heard about!

CppCon 2019: A Unifying Abstraction for Async in C++--Eric Niebler, David Hollman

By Adrien Hamelin | Aug 7, 2020 12:44 PM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

A Unifying Abstraction for Async in C++

by Eric Niebler, David Hollman

Summary of the talk:

Async in C++ is in a sad state. The standard tools -- promises, futures, threads, locks, and std::async -- are either inefficient, broken, or both. Even worse, there is no standard way to say _where_ work should happen. Parallel algorithms, heterogeneous computing, networking & IO, reactive streams, and more: all critically important foundational technologies that await a standard abstraction for asynchronous computation.

In this talk, Eric Niebler and David Hollman dig into the Standard Committee's search for the basis operations that underpin all asynchronous computation: the long-sought Executor concept. The latest iteration of Executors is based on the Sender/Receiver programming model, which provides a generalization of many existing paradigms in asynchronous programming, including future/promise, message passing, continuation passing, channels, and the observer pattern from reactive programming. It also has surprising and deep connections to coroutines, which further demonstrates the model’s potential to be a truly unifying abstraction for asynchronous programming in C++20 and beyond.

Eric and David will present the short-term and long-term directions for Executors in ISO Standard C++, illustrating the design by walking through several implementation examples. They will talk about the direct connection between coroutines and the Sender/Receiver model and discuss what it means for the future of asynchronous APIs in C++. Finally, they will cover how the restrictions imposed by the Executors model should affect the way you write code today so your code is ready for the next big revolution in parallel and concurrent C++ programming.

CppCon 2019: Everyday Efficiency: In-Place Construction (Back to Basics?)--Ben Deane

By Adrien Hamelin | Aug 5, 2020 09:31 AM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

Everyday Efficiency: In-Place Construction (Back to Basics?)

by Ben Deane

Summary of the talk:

Efficient C++ has always been about minimizing copies. This practically-focused
talk is about how to do that when working with move semantics, perfect
forwarding and STL containers, or non-STL containers that present similar
interfaces.

In-place construction is an easily stated goal, but can be really fiddly to get
right, especially given the foibles of various container interfaces. We'll talk
about copy elision; when to use emplace, insert, or other methods; vectors,
maps, optionals, variants; and how things change from C++11 through C++20.
Attendees will learn why in-place construction is beneficial and exactly how to
achieve optimal efficiency with the various standard container types.

CppCon 2019: 10 Techniques to Understand Existing Code--Jonathan Boccara

By Adrien Hamelin | Aug 3, 2020 11:29 AM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

10 Techniques to Understand Existing Code

by Jonathan Boccara

Summary of the talk:

One of the reasons why a lot of us work in C++ is because there is a huge amount of existing projects written in C++.

But existing code can be hard to understand.

In this presentation, you will learn how to make sense of code quickly, from the general big picture of the codebase all the way down to the little details of the code of a complex class.

The ten rules covered in this session will teach you to:
- start reading code from the end
- identify the parts of code that carry the most information
- locate the code of any feature visible in the application
- and many more!

Code reading techniques usually come with years and years of experience. This presentation will teach some of them to you right now, supported by code examples.

There is a wealth of talks about how to write C++ code using the latest features of the language, but there are very few talks about reading existing code. In particular the everyday code that people have in their codebases. And as the saying goes, code is read much more often than it is written.

This presentation aims at filling this need in a practical way, by exposing 10 techniques that conferences attendees can use on an everyday basis to understand quickly the code they get to work on, as soon as they go back to the office after the conference.