CppCon 2026

To write the best C++ application code, you must think like a library author. This talk reframes application development as a form of library design, where every component is a potential asset for future maintenance and extension.

We'll survey the C++ language features that empower library authors to create powerful, flexible, and safe abstractions. From there, we'll distill the 'library author mindset.’ You will leave with concrete principles and techniques to make your application code more modular, maintainable, composable, reusable, testable, and ultimately, more valuable.

As legacy C++ codebases evolve to meet new requirements, fix architectural issues, and address performance bottlenecks, refactoring becomes inevitable — but full rewrites are risky, costly, and rarely practical. This talk explores how modern C++ features — especially functional programming techniques and type erasure — can be used to refactor and extend legacy systems. We will present a concrete, low-risk, and measurable four-step technical framework for incremental modernization, by leveraging pure functions, discriminated union types, and type-erased callables to achieve safer, more flexible code with compile-time guarantees, even in traditionally object-oriented codebases.

The core of the talk will walk through the entire process on a concrete code example, illustrating (1) how to isolate existing logic, (2) define safer data models using immutable types, (3) deploy type erasure to create a robust, non-disruptive adapter boundary between old and new code, and (4) measurably execute the migration with safe testing practices. We will also share lessons learned from real-world experience and conclude by showing how these foundational patterns can be extended into future-thinking designs, leveraging examples with accepted C++26 features. Every step is grounded in real production constraints and trade-offs, and the techniques transfer directly to any domain where full rewrites are not an option. Attendees will walk away equipped with practical strategies to incrementally refactor your legacy systems without sacrificing stability or velocity.

C++ lifetime management is fundamentally built around synchronous scope exit. Constructors establish invariants, destructors release resources, and RAII permits ownership and cleanup to compose naturally with ordinary control flow. Asynchronous systems disrupt this model. Destruction may itself require asynchronous work, and “just launch another task in the destructor” quickly turns deterministic lifetime management into unstructured background activity.

This talk explores the implementation of async lifetime management in std::execution, based on the enter/exit scope sender framework proposed in P3955. Rather than treating async construction and destruction as special cases, the model reframes them as composable asynchronous protocols built around explicit async scope entry and exit operations. The talk follows the process of turning these ideas into working code, beginning from the low-level enter/exit sender abstractions and progressively assembling higher-level lifetime facilities on top. Along the way, the implementation uncovers an important self-similarity in the problem domain: Higher-level async lifetime facilities can themselves be expressed in terms of the same lower-level async lifetime primitives.

The implementation discussion focuses on the machinery required to make these guarantees real: Coordinating async teardown within structured concurrency, managing partially-entered scopes, and preserving deterministic cleanup semantics even when destruction itself becomes asynchronous. The resulting design serves both as a practical exploration of async lifetime management and as a case study in how implementing an abstraction can reveal deeper structural properties hiding inside the model itself.

In this talk we will explore "Concepts," a powerful feature for expressing template requirements added in C++20. Participants will learn how concepts improve code readability, provide clearer compiler diagnostics, and help enforce correct usage of templates and function overloading. Through simple, hands-on examples, we will explore the syntax, common use cases, and best practices for integrating concepts into modern C++ code. By the end of the session, attendees will understand how to write safer, more maintainable template code and leverage concepts to communicate intent clearly.