CppCon 2026

Move semantics and perfect forwarding, introduced in C++11, are quite impactful features that still remain a source of confusion even for some experienced developers. This talk builds understanding from the ground up: what problem move semantics solves, how rvalue references enable it, and why the rules work the way they do.

We start with the cost of unnecessary copies and how move constructors and move assignment operators let us transfer resources instead of duplicating them. We then look at how std::move doesn't actually move anything — and what it really does. From there we tackle the forwarding problem: why writing a single function that preserves the value category of its arguments is necessary, how forwarding references (also known as "universal reference" in the past) solve it, and what std::forward does under the hood.

Along the way we cover the practical details that trip people up: reference collapsing rules, the interaction between overload resolution and reference binding, when the compiler generates move operations and when it doesn't, and the cases where std::move can actually pessimize your code. We also discuss trade-offs in parameter passing — by value, by const reference, or by forwarding reference — so attendees should have a clearer model for making these decisions in their own code.

At the end we will look into std::forward_like and explore how it is different from std::forward .

No prior knowledge of rvalue references is assumed. Familiarity with copy constructors, destructors, and basic templates is helpful.

C++ templates are one of the language’s most powerful yet often misunderstood features. This talk walks the audience through the entire template landscape, starting with the basic syntax and definition, moving through function and class templates, and culminating in advanced techniques.

Attendees will learn how template argument deduction works, why implicit requirements matter, and how explicit specialization can replace error-prone macro tricks. Real-world examples, including a flexible register abstraction used in production code, show how generic programming can deliver type-safe, high-performance solutions without sacrificing readability and performance (zero cost abstraction).

By the end of the session, participants will feel confident writing their own generic components, understand the trade-offs of different template features, and have a toolbox of best-practice patterns they can apply immediately to their projects.

In the C++ ecosystem, we have powerful tools for understanding our programs before, during, and after they run. But compiler warnings, clang-tidy, cppcheck, sanitizers, debuggers, profilers, and coverage tools all answer different questions, and using them well starts with knowing which question you are asking.

This talk introduces code analysis from first principles. We will compare static techniques such as compiler diagnostics, linting, and include analysis with runtime techniques such as sanitizers, coverage instrumentation, and profiling. We will also briefly connect these tools to the direction of modern C++, including C++26 contracts and standard library hardening, where some assumptions that used to live only in comments, documentation, or debug modes become part of the program's checkable structure. Through small C++ examples, we will see what each category of tool can reveal, what it cannot prove, and how the tools complement each other.

Attendees will leave with a practical mental model for choosing the right analysis tool for the task at hand, interpreting its output, introducing analysis into an existing C++ codebase, and writing code that is easier for both humans and tools to understand.

C++ gives us at least four different ways to pass "a thing that can be called" from one piece of code to another: function pointers, function objects, lambdas, and type-erased wrappers like std::function . Modern C++ has added more — generic lambdas, deducing-this lambdas, std::move_only_function , and a healthy ecosystem of concept-constrained callable parameters. Each of these has a job it is good at and several jobs it is bad at, but they are often used interchangeably until something breaks.

We will start with the basics: what a callable actually is, how function pointers, function objects, and lambdas relate to one another, and how the compiler thinks about each of them. We will look at lambda capture rules in detail — by-value, by-reference, init captures, dangling captures, and the cases where well-meaning developers reach for [=] or [&] and ship a bug — and we will see how generic lambdas (C++14) and deducing-this lambdas (C++23) extend the model without giving up clarity.

From there we will turn to the question of how to store and pass callables. We will compare function pointers, std::function , std::move_only_function (C++23), and concept-templated callable parameters along the axes that actually matter: ownership, allocation, move-only support, performance, and what the API tells the reader. Examples will be drawn from issues that have come up writing production code and mentoring developers — including the kind of subtle ABI and lifetime bugs that hide behind a perfectly reasonable-looking std::function<void()> parameter.

We will conclude with recommendations for which tool to reach for in which situation, with reference to the C++ Core Guidelines where useful. Attendees will leave with a clearer mental model of callables in modern C++ and a defensible default for the next time they write a function that takes one.

In modern C++, std::unordered_map is the de facto #2 container. Its dominance signifies a fundamental shift in application design: the performance-critical need for O(1) average-case key-value lookups.

Join as we move beyond "just use a hash map" and explore the critical, real-world implications of this choice. We'll start by benchmarking the classic std::map (red-black tree) against std::unordered_map (hash table) to understand exactly what you gain-and what you might lose.

However this power comes with risks. An average-case O(1) can quickly degrade to a catastrophic O(n) without warning. We will profile and dissect the actual costs of using a hash map:

• The Hash: What makes a good hash function? We'll go beyond std::hash and see how to write effective, fast hashers.
• The Collision: How do different collision-handling strategies impact performance and memory?
• The Re-hash: What is "load factor," and when does the hidden cost of a full table re-hash destroy your performance gains?

We'll conclude with a practical decision-making framework for when to choose std::unordered_map , when to fall back on the ordered std::map , and how std::string -the container we often forget is a container-fits into this modern landscape.

You will leave this session knowing precisely which data structure to deploy for maximum performance.

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.

Modern programming languages offer powerful tools for creating intuitive, expressive code, but few are as frequently debated as function and operator overloading. While these features allow developers to write code that mimics natural mathematical notation, such as A+B for complex numbers or vectors, they also introduce significant risks of ambiguity, hidden performance costs, and unintuitive behavior if misused.

This talk explores the balance between expressive power and code maintainability. We will dive into the mechanics of compile-time polymorphism, examining how compilers resolve overloaded calls and the strict rules governing arity, precedence, and associativity. Beyond the what and the how, we will talk about the when and the why with examples.

Every software engineer needs to understand the fundamentals of how your computer works. My mantra for teaching computer systems is 'no more magic', and in this talk I'll do my best to dispel what feels like 'magic' in our hardware in a single hour. In this talk, we will investigate '3' pictures of the 'the compilation process', 'program stack', and a 'cpu' to understand how these components work together to ultimately compile and execute code. An emphasis during this talk will focus on the 'CPU' and the hardware components (e.g. registers, cache memory, main memory, page table) interact with the operating system to efficiently execute a program. Hardware will be presented side-by-side with code so we can understand what happens in the hardware as software executes. Attendees will leave this talk with a better mental model of how their hardware works, and the implications their software design choices have on performance.

A fundamental control structure of each programming language are loops. And we all expect them to be simple and self explanatory. However, C++ would not be C++, if there would be no tricky details to learn and respect about loops in C++.

This talk takes its time to discuss the various ways and approaches to program loops in C++. Beside basic while and for loops, we talk about the range-based for loop, and all the extensions recently added to these control structures.

In addition, we will look at other ways to program loops in C++, such as using algorithms and how to deal with parallel computing in a loop.

As a result you get a deeper understanding of the various ways loops can be programmed in Modern C++ so that you know better how to use them in practice.

Have you ever wondered why your C++ class suddenly doubled in size, or why reordering its members made it smaller? This talk introduces memory alignment in C++ from the ground up - what it is, why it is critical, and how compilers handle it under the hood. We’ll start from first principles: how modern CPUs read memory, the difference between aligned and unaligned access, and the performance costs of getting it wrong. Using benchmarks, we’ll see just how impactful misalignment can be. From there, we’ll dive into how compilers lay out data members in structs and classes, and how simple reordering can reduce memory footprint. Live coding examples will illustrate how padding is introduced and how tools like alignas, alignof, and std::align give you precise control. We’ll also look at packed data structures, which trade alignment guarantees for compactness - common in network protocols. While they can save space, they also introduce risks like undefined behavior when misused. Through real-world examples, you'll learn when packed structures make sense, and when they’re a hazard. By the end of the talk, you'll walk away with a solid intuition for alignment and the confidence to manage memory layout effectively in your programs.

How to Choose and Use the Right Container in Modern C++: Part 1, Classic Containers

Choosing the right container and using it correctly can have a profound impact on the performance of a program, but doing so is harder than you might think. In Part 1 we will survey the containers and adaptors in the C++17 Standard Library, and discuss how to choose the best tool for the job and extract the best performance from it. We will consider the abstractions they model and the practical limitations they impose, and find that choosing between them requires an understanding not only of the speed and size tradeoffs of each container, but also of the difference between algorithmic complexity and actual behavior. And we will flag aspects of the standard containers that, without this understanding, can lead you to the wrong choice.

How to Choose and Use the Right Container in Modern C++: Part 2, New and Future Containers

Choosing the right container and using it correctly can have a profound impact on the performance of a program, but doing so is harder than you might think. In Part 2 we will survey the new containers and adaptors introduced to the Standard Library in C++23/26, and discuss how to choose the best tool for the job and extract the best performance from it. We will consider the abstractions they model and the practical limitations they impose, and find that choosing between them requires an understanding not only of the speed and size tradeoffs of each container, but also of the difference between algorithmic complexity and actual behavior. And we will examine a proposal for a future container that diverges from the historical STL design principles and ask: what makes for a good container design?

Most C++ programmers are familiar with the traditional C++ facilities for text processing found in the iostream and string libraries. However, std::format (C++20) and std::print (C++23) provide new text formatting tools that are unfamiliar to many C++ programmers. While these new facilities can be very helpful, they can also produce some very intimidating error messages when misused. Moreover, the process for writing your own user-defined types that you can format with std::format and std::print is not very straightforward.

This session starts with an overview of the traditional C and C++ text processing libraries. It then shows how std::format and std::print neatly combine benefits from both the C and C++ libraries to create a safer, more convenient interface. After that, this session explains the steps you must take to write user-defined types that work cleanly with std::format and std::print. You’ll leave this session with a clearer understanding of the benefits of using these new text formatting facilities and how to integrate them into your existing code base.

const is one of the oldest and most widely used features in C++, yet many developers still struggle with the subtle differences between const , constant expressions, constexpr , and consteval .

In this talk, you will learn how compile-time constants evolved in modern C++, starting with const and continuing through the features introduced since C++11. You will see what constant evaluation really means, what the compiler is allowed to execute during compilation, and where the limits still are today.

Using practical examples, we will explore when const is enough, when constexpr is needed, and how compile-time and runtime execution interact in modern C++. We will also look at common pitfalls, surprising behavior, and cases where compile-time programming can either improve code or make it harder to understand.

Finally, you will see how features such as consteval and std::is_constant_evaluated influence correctness, testing, and maintainability.

By the end of this talk, you will have a deeper understanding of constant evaluation and know how to use modern compile-time features more effectively in your code.