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CppCon 2017: Concurrency, Parallelism and Coroutines--Anthony Williams

Have you registered for CppCon 2018 in September? Early bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Concurrency, Parallelism and Coroutines

by Anthony Williams

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

C++17 is adding parallel overloads of most of the Standard Library algorithms. There is a TS for Concurrency in C++ already published, and a TS for Coroutines in C++ and a second TS for Concurrency in C++ in the works.

What does all this mean for programmers? How are they all related? How do coroutines help with parallelism?

This session will attempt to answer these questions and more. We will look at the implementation of parallel algorithms, and how continuations, coroutines and work-stealing fit together. We will also look at how this meshes with the Grand Unified Executors Proposal, and how you will be able to take advantage of all this as an application developer.

CppCon 2017: Objects, Lifetimes, and References, oh my...--Nicole Mazzuca

Have you registered for CppCon 2018 in September? Early bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Objects, Lifetimes, and References, oh my...

by Nicole Mazzuca

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

How does the C++ abstract machine really work at the lowest levels? Why does the committee design its rules the way they do? Gain insight into the object model of C++, from references to passing semantics to copy elision. C++ is a complicated language full of arcane rules and complicated tangents - learn how it's all tied together in this basic model of locations, objects, and values.

CppCon 2017: Runtime Polymorphism: Back to the Basics--Louis Dionne

Have you registered for CppCon 2018 in September? Early bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Runtime Polymorphism: Back to the Basics

by Louis Dionne

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

C++ solves the problem of runtime polymorphism in a very specific way. It does so through inheritance, by having all classes that will be used polymorphically inherit from the same base class, and then using a table of function pointers (the virtual table) to perform dynamic dispatch when a method is called. Polymorphic objects are then accessed through pointers to their base class, which encourages storing objects on the heap and accessing them via pointers. This is both inconvenient and inefficient when compared to traditional value semantics. As Sean Parent said: Inheritance is the base class of evil.

It turns out that this is only one of many possible designs, each of which has different tradeoffs and characteristics. This talk will explore the design space for runtime polymorphism in C++, and in particular will introduce a policy-based approach to solving the problem. We will see how this approach enables runtime polymorphism with stack-allocated storage, heap-allocated storage, shared storage, no storage at all (reference semantics), and more. We will also see how we can get fine-grained control over the dispatch mechanism to beat the performance of classic virtual tables in some cases. The examples will be based on a real implementation in the Dyno library [1], but the principles are independent from the library.

At the end of the talk, the audience will walk out with a clear understanding of the different ways of implementing runtime polymorphism, their tradeoffs, and with guidelines on when to use one implementation or another.

CppCon 2017: Fuzz or lose...--Kostya Serebryany

Have you registered for CppCon 2018 in September? Early bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Fuzz or lose...

by Kostya Serebryany

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Fuzzing is a family of testing techniques in which test inputs are generated semi-randomly. The memory unsafety of C++ has made fuzzing a popular tool among security researchers. Fuzzing also helps with stability, performance, and equivalence testing; and it’s a great addition to everyone’s CI.

Our team has launched OSS-Fuzz, the Google's continuous fuzzing service for open source software, and a similar service for our internal C++ developers. Over 1000 C++ APIs are being fuzzed automatically 24/7, and thousands of bugs have been found and fixed.

Now we want to share this experience with the wider C++ community and make fuzzing a part of everyone’s toolbox, alongside unit tests. We will demonstrate how you can fuzz your C++ library with minimal effort, discuss fuzzing of highly structured inputs, and speculate on potential fuzzing-related improvements to C++.

CppCon 2017: dynamic_cast From Scratch--Arthur O'Dwyer

Have you registered for CppCon 2018 in September? Early bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

dynamic_cast From Scratch

by Arthur O'Dwyer

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

This session will introduce you to the C++ object model: the rules by which C++ class objects are translated into memory layouts. We'll quickly cover polymorphic class types and multiple and virtual inheritance. We'll discuss the anatomy of a virtual method call, the difference between `static_cast` and `reinterpret_cast`, and what's contained in a vtable besides function pointers. We'll see that the way `dynamic_cast` thinks about the class hierarchy is slightly different from the way we're used to drawing it; and that `dynamic_cast` is expensive enough that sometimes we can find cheaper ways to ask an object for its type! The climax will be a complete, bug-free, and fast implementation of C++'s built-in `dynamic_cast`, using our own hand-crafted artisanal run-time type information (RTTI).

Attendees will incidentally be exposed to several features of the modern C++ language, including type traits and the `final` qualifier.

This session will mostly be talking about the Itanium C++ ABI, which is the standard on Linux and OS X systems. Mapping these concepts to the MSVC ABI will be left as an exercise for the reader of the project's GitHub repo: https://github.com/Quuxplusone/from-s...

The first 5 companies have joined the employer listing at Meeting C++!

Since this year, Meeting C++ offers companies the option to be listed as a C++ employer:

The first 5 companies have joined the employer listing!

by Jens Weller

From the article:

Happy to report that now 5 companies are listed in the employer listing in the Meeting C++ job section!

These are:

    KDAB
    QuasarDB
    think-cell
    Tenzir
    Rieke Computersysteme

ISO C++ Committee – Rapperswil 2018 trip report--Timur Doumler

MAny things happened!

ISO C++ Committee – Rapperswil 2018 trip report

by Timur Doumler

From the article:

From the 4th to the 9th of June 2018, Phil Nash and I attended the ISO C++ Committee meeting in beautiful Rapperswil, Switzerland, representing JetBrains. We are continuing our active involvement in developing and standardising C++ (please read the last trip report for details)...

Overload 145 is now available

ACCU’s Overload journal of June 2018 is out. It contains the following C++ related articles.

Overload 145 is now available

From the journal:

Automate all the things
Automation can speed things up. Frances Buontempo considers how it can make things worse. by Frances Buontempo

How to Write a Programming Language: Part 1, The Lexer
Writing a programming language might sound very difficult. Andy Balaam starts his series with a lexer. by Andy Balaam

Type-agnostic Tracing Using {fmt}
Tracing compound and custom types is a challenge. Mike Crowe demonstrates how {fmt} provides a safe alternative to printf. by Mike Crowe

A Short Overview of Object Oriented Software Design
Object oriented design has many principles. Stanislav Kozlovski demonstrates good design through a role playing game. by Stanislav Kozlovski