Video & On-Demand

CppCon 2017: Delegate this! Designing with delegates in modern C++—Alfred Bratterud

Have you registered for CppCon 2018 in September? 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:

Delegate this! Designing with delegates in modern C++

by Alfred Bratterud

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Designing a fast IP stack from scratch is hard. Using delegates made it all easier for IncludeOS, the open source library operating system written from scratch in modern C++. Our header-only delegates are just as fast as C-style function pointers, compatible with std::function, and allows any object to delegate work to stateful member functions without knowing anything about the class they belong to. We use delegates for everything from routing packets to creating REST endpoints, and most importantly to tie the whole IP stack together. In this talk we’ll show you how we use delegates in IncludeOS, discuss pitfalls and alternatives, and give you all you need to get started.

CppCon 2017: Coroutines: what can’t they do?—Toby Allsopp

Have you registered for CppCon 2018 in September? 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:

Coroutines: what can't they do?

by Toby Allsopp

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Coroutines are coming. They're coming for your asynchronous operations. They're coming for your lazy generators. This much we know. But once they're here, will they be satisfied with these offerings? They will not. They will require feeding, lest they devour our very souls. We present some fun ways to keep their incessant hunger at bay. I, for one, welcome our new coroutine overlords.

The Coroutines Technical Specification is an experimental extension to the C++ language that allows functions to be suspended and resumed, with the primary aim of simplifying code that invokes asynchronous operations. We present a short introduction to Coroutines followed by some possibly non-obvious ways they can help to simplify your code.

Have you ever wanted to elegantly compose operations that might fail? Coroutines can help. Have you ever wished for a zero-overhead type-erased function wrapper? Coroutines can help. We show you how and more.

CopperSpice: Special Member Functions

New video on the CopperSpice YouTube Channel:

Special Member Functions

by Barbara Geller and Ansel Sermersheim

About the video:

This video discusses special member functions in C++. We examine what they are, how they work, and some operations which seem like they would be special member functions but are not. We also briefly discuss the spaceship operator, coming in C++20, and the implications it has for the list of special member functions.

Please take a look and remember to subscribe!

CppCon 2017: Agent based class design—Odin Holmes

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:

Agent based class design

by Odin Holmes

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Abstracting a set of functionalities into a class which provides a higher level interface often requires tough design decisions. Users who do not have the exact requirements for which the abstraction is optimized will suffer a syntactic or run time overhead as a result. Alexandrescu's famous "policy-based design" provides a mechanism to allow the user to extend and customize an existing abstraction in order to fine-tune its functionality for many different use cases. This is however limited to use cases where each policy more or less represents a compile time strategy pattern.

Alas, not everything is a strategy pattern. In this talk I will explore the viability of a more agent-pattern-like paradigm where each policy knows its requirements and publishes its capabilities. In this paradigm, glue code connecting any valid set of policies is automatically generated using template metaprogramming. This allows much more powerful customizations while maintaining static linkage.

CppCon 2017: Concurrency, Parallelism and Coroutines—Anthony Williams

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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.

CppCast Episode 156: SG15 Tooling Group with Titus Winters

Episode 156 of CppCast the only podcast for C++ developers by C++ developers. In this episode Rob and Jason are joined by Titus Winters from Google to discuss the SG15 Tooling Study Group and revisiting the concept of regular types.

CppCast Episode 156: SG15 Tooling Group with Titus Winters

by Rob Irving and Jason Turner

About the interviewee:

Titus Winters has spent the past 7 years working on Google's core C++ libraries. He's particularly interested in issues of large scale software engineer and codebase maintenance: how do we keep a codebase of over 100M lines of code consistent and flexible for the next decade? Along the way he has helped Google teams pioneer techniques to perform automated code transformations on a massive scale, and helps maintain the Google C++ Style Guide.

CppCon 2017: A modern formatting library for C++—Victor Zverovich

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:

A modern formatting library for C++

by Victor Zverovich

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Come learn about the intricacies of C++ formatting, from stdio to iostream to the new standard proposal P0645R0: Text Formatting. The new proposal combines variadic templates with a Python-like format string syntax and is designed for performance, extensibility, and safety. It is based on the popular fmt library that has been successfully used in numerous projects in such diverse areas as gaming, mathematical optimization, autonomous vehicles, databases, logging libraries and more.

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.