CppCon 2026

C++20 coroutines come with a reputation for complexity — and writing your own coroutine return type deserves that reputation. But here is the good news: you probably don't have to. With std::generator in C++23, high-quality libraries like Asio and cppcoro today, and std::task on its way in C++26, most developers can simply write co_await and move on.

There is one gap, however. Sooner or later, every developer using coroutines needs to bridge an existing asynchronous interface — a timer, an I/O operation, a thread pool callback, a legacy future — into the coroutine world. That bridge is built with awaiters and awaitables, and that is exactly what this session teaches.

We will start from first principles: what does co await actually do? We will demystify the three functions that form the awaiter protocol — await ready, await suspend, and await resume — and build a clear mental model for each. We will implement a real awaiter from scratch, then explore how symmetric control transfer keeps the call stack flat across deeply chained async operations. Next, we will learn how to make any existing type co await-able without modifying it, using operator co await, and how await transform lets you restrict or adapt awaitable behavior to a specific coroutine context. Finally, we will look at how to write cancellation-aware awaiters using std::stop token, so your coroutines respond promptly when work is no longer needed.

No prior coroutines experience is assumed. If you know what co await looks like on the surface but not what happens underneath it, this session is for you. You will leave with both the knowledge and the code to wrap any asynchronous operation into a first-class co await expression.

As of C++11 there are 6 special member functions that the compiler will generate for us if we don't do anything to get in the way.

But there are many other member functions, in the form of comparison operators, that we can =default explicitly

Which of these should we =default? How do we help the compiler, or stay out of its way?

How many do we need to implement? When can you trust the compiler or not?A

Queues are the backbone of concurrent systems — yet most C++ developers treat them as a black box. Pick the wrong queue topology, misplace an alignas, or use the wrong memory order, and you pay for it in microseconds of latency, invisible cache thrashing, or subtle correctness bugs that only manifest under load. This talk is a rigorous, bottom-up treatment of the four canonical concurrent queue topologies: SPSC, MPSC, SPMC, and MPMC. We start with the hardware reality — how cache coherence protocols turn innocent struct layout into a performance disaster through false sharing — and build upward through the C++ memory model, atomic operations, and queue algorithm design. For each topology, we derive the minimal set of memory ordering guarantees required for correctness, show how to exploit producer/consumer asymmetry to eliminate unnecessary synchronization, and demonstrate how alignas(std::hardware destructive interference size) and deliberate padding can be the difference between 100ns and 10ns throughput. We dissect Dmitry Vyukov's MPMC ring buffer, the intrusive MPSC queue, and Michael-Scott's linked-list queue — not just their interfaces, but the why behind every memory order acquire and every phantom cache line. We then go beyond correctness into the practical engineering tradeoffs: bounded vs unbounded, throughput vs latency, contention vs coordination overhead. Real benchmark data shows how these decisions interact non-obviously — an MPMC queue can outperform MPSC under certain producer counts, and seq cst where you don't need it can quietly halve your throughput. Attendees will leave with a clear mental model for choosing and implementing the right queue for their threading topology, a checklist for false sharing audits, and battle-tested code patterns suitable for low-latency production systems.

Modern C++ gives developers powerful tools to write cleaner, safer, and more expressive code — but many production codebases still suffer from excessive boilerplate, repetitive patterns, and verbose implementations inherited from older C++ styles.

This talk explores practical modern C++ techniques that significantly reduce lines of code while preserving readability, maintainability, and runtime performance.

Through real-world examples, we will refactor traditional C++ implementations using features such as ranges, structured bindings, constexpr, concepts, CTAD, lambdas, std::optional, std::variant, and std::expected. We will examine where these features genuinely improve code quality — and where they can accidentally hurt clarity or performance if misused.

The session also goes beyond syntax improvements by analyzing generated assembly, compiler optimizations, allocations, and benchmark results to validate whether “shorter” code truly remains zero-cost.

Attendees will leave with practical patterns they can immediately apply to modernize existing codebases, reduce unnecessary complexity, and write more expressive C++ without sacrificing performance.

Boost has always been run by its community. Nothing got in without review, nobody's library was above being argued. The Boost.Documentary filmmakers want their film held to the same standard. Join the test screening and ensure your thoughts are reflected in the general release cut!

The True Stories team will be on site during this Audience Preview Screening.

True Stories is the two-time Image Award-nominated production company of Collier Landry and Ray Nowosielski. They met on the production of A Murder in Mansfield, bringing to life Landry’s personal story for Warner Discovery, and have since together and solo led the productions of Emmy- and awards-nominated documentaries, including 1946: The Mistranslation that Shifted Culture, Desert One (HISTORY), Gumbo Coalition (HBO Max), Reservation Redemption, The Super Models (AppleTV), and Tricky Dick and the Man in Black (Netflix), and podcasts, including After the Uprising (iHeartMedia), The Collier Landry Show (YouTube), Finding Mom’s Killer (Sony/The Binge) and Moving Past Murder (YouTube).