CppCon 2021 Online Keynote: Six Impossible Things by Kevlin Henney

We’ve previously announced keynotes by Bjarne Stroustrup, Herb Sutter, Lisa Lippincott, Michael Caisse, and Sean Parent. This is the last of our six conference keynotes to be announced...

A (Short) Tour of C++ Modules

Thursday, October 28 • 10:30am - 11:30am

by Daniela Engert

Modules are probably the most impactful and most transformative recent major addition to the C++ language. From a user perspective, Modules are conceptually simple and the idea is easy to grasp. And with the C++20 ecosystem maturing, using Modules and adopting them into every-day programming is both feasable and advantageous.

But what is the motivation that lead to the invention of Modules and their inclusion into the standard? How do they look like? Which are the three key features of C++ Modules that exist since the inception of the language, that are mostly irrelevant in the typical usage of 'classical' C++ such that hardly any programmer needs to know much about them but a Modules developer does? What surprises might lie on the path of transforming a classical library into a Module? Are there still any issues, loose ends or open questions regarding Modules?

The talk will try to give a comprehensive answer to those questions. The audience shall get enough information to decide when the right time has come for them to take the plunge and move their codebase to Modules wherever it is advantageous.

CppCon 2021 Keynote: Warning: std::find() is Broken! by Sean Parent Live, In Person

We’ve previously announced keynotes by Bjarne Stroustrup, Herb Sutter, Lisa Lippincott and Michael Caisse. This is the fifth of our six conference keynotes to be announced...

Call for Papers

by the ACCU

The ACCU 2022 conference will be from 2022-04-06 to 2022-04-09, with a pre-conference workshops on 2022-04-05.

The ACCU 2022 will be a hybrit event.

Historically, ACCU has a lot of C++ and C content, and is proud of that: ACCU is the foremost annual conference for people interested in C++ and C, at least in and around the UK. But it is not just a C++ and C conference, ACCU is about programming in whatever language people are using, with whatever tools and processes people are using: D, Chapel, Java, Kotlin, C#, F#, Groovy, Rust, Go, Python, Ruby, Lisp, to name just a few programming languages about which there have been sessions at ACCU conferences. Git, Mercurial, CMake, Meson, TDD, BDD, allthese tools and techniques have been the focus of sessions at ACCU. The ACCU Conference is looking for sessions that will be interesting to people who create software.
The ACCU Conference is put on by ACCU (https://accu.org), but is open to anyone who wishes to be there either as a presenter or an attender.

The Call for Papers lasts for about 3 weeks and will close on Friday 5th November 2021 at 23:59:59 GMT.

Highlighting two events next week

by Jens Weller

The two events will be on Wednesday and Thursday evening (CEST/Berlin):

• The Meeting C++ online book & tool fair
• The monthly meeting with Andreas Reischuck speaking about Using C++20 Coroutines for Asynchronous Parsers.

C++20’s ＜chrono＞ Calendars and Time Zones in MSVC

Thursday, October 28 • 10:30am - 11:30am

by Miya Natsuhara

The ＜chrono＞ header has existed since C++11, but C++20 dramatically increased its capabilities. MSVC has completed this C++20 feature and this session will focus on the development of our implementation and Windows-specific considerations that we encountered. For instance, how do we know if a given point in time is during a leap second insertion? Where do we get the data for time zones? If you are excited by these new chrono features and want to support a Windows platform, come and learn about its developments and caveats for a Windows implementation!

We will also touch on how STL maintainers and our valued external contributors developed the new features collaboratively. If you’re interested in participating in our open-source repo by reporting issues, contributing to discussions, or submitting pull requests, we hope that hearing about an example of collaboration will encourage you to visit our repo in the future.

From Problem to Coroutine: Reducing I/O Latency

Wednesday, October 27 • 10:30am - 11:30am

by Cheinan Marks

Coroutines are now officially part of the C++20 standard and one of their advertised uses is reducing I/O latency. Almost all of the literature on coroutines that I found illustrated either synchronous generators or described the nitty gritty details of coroutines using very simple usages. The best talk I found was Gor Nishanov's excellent talk from CppCon 2018, "Nanocoroutines to the Rescue!" (go watch it!) which solves a different problem than mine, but mostly illustrates the power of coroutines.

In this talk I want to approach coroutines from another direction. I will start with the problem, which almost all engineers face in some form, that of reducing I/O latency while searching and gathering data from a sequential file. Instead of going into the details of how the coroutines work, I will start with the naive synchronous solution and build up coroutines step by step to try and reduce latency, illustrating the pieces as they are added.

Finally I will compare this solution to an old-fashioned solution using threads and we'll see how the coroutines performance measures up and whether all the additional boilerplate needed is worth the additional trouble. I hope discussing the value of coroutines and future proposals for RAII and executors will spark a good discussion with the audience.

Improved Null Pointer Dereference Detection in Visual Studio 2022 version 17.0 Preview 4

by Gabor Horvath

The C++ static analysis team is committed to making your C++ coding experience as safe as possible. We are adding richer code safety checks and addressing high impact customer feedback bugs posted on the C++ Developer Community page. Thank you for engaging with us and giving us great feedback on the past releases and early previews leading to this point. Below is the detailed overview of a new experimental code analysis check that can detect null pointer dereference errors, along with a comparison to an existing check that has the same purpose...

Embracing PODs Safely Until They Die

Thursday, October 28 • 10:30am - 11:30am

by Alisdair Meredith and Nina Ranns

How do you change the active member of a union? Can you copy an object without
a publicly callable copy constructor? Can you pass classes having private data to
a function implemented in C? What is the use case for the library type trait
`std::is_trivially_move_assignable`? All these questions and more will be answered
in this session.

PODs --- Plain Old Data --- are neither plain nor old in C++11, and continued to
evolve in every published standard since, until they were finally banished in C++20.
In researching the deconstruction of PODs for the upcoming book, "Embracing
Modern C++ Safely" Alisdair Meredith (and the other authors including John
Lakos, Vittorio Romeo, and Rostislav Khlebnikov) discovered that many of the
intuitive properties and capabilities of trivial and standard layout types did not
behave quite as expected, and there are many subtleties waiting to catch the
unwary. Nina Ranns, as an active member of the Core working group, stepped in
to explain and resolve many concerns, while pointing out further bad assumptions.
Together they will present the use cases, pitfalls, and annoyances of these features
as now properly understood, giving a flavor of the presentation style of each of the
57 C++11/14 features presented in the book.

Compiler Explorer with Cmake

by Gajendra Gulgulia

Compiler explorer has been one of the most widely used online tool for compiling C++ code, doing experiment with C++ features, sharing code snippets with friends and colleagues and also (my favorite feature) to compare and prove with the help of assembly code why a certain way of coding might be good or bad compared to another way.
Recently compiler explorer added support for compiling multiple files with CMakeLists.txt [1] . This opens up a new possibilities for developers around the world from testing complex pieces of code to testing the compilation behavior of the same.
In this issue, I would like to give a walk through on how to set up a simple layout of three files compiled with CMakelists.txt. Note that the focus is on setting up compiler explorer for multiple files and not on code efficiency. Also the article might at first glance look lengthy, but it may only be due to 19 images in the tutorial. So don’t get weighed down by the size of the article and lets start!