Constexpr STL Containers: Why C++20 Still Falls Short - Sergey Dobychin - CppCon 2025 скачать в хорошем качестве

Constexpr STL Containers: Why C++20 Still Falls Short - Sergey Dobychin - CppCon 2025

https://cppcon.org​ --- Constexpr STL Containers: Why C++20 Still Falls Short - Sergey Dobychin - CppCon 2025 --- One of the most powerful features that sets C++ apart from many other languages is its ability to perform complex constant evaluation at compile time using constexpr. With each new language standard, these capabilities have expanded — and C++20 took a big step forward by allowing dynamic memory allocation in constexpr functions via operator new. This made it possible, for example, to use containers like std::vector and std::string in constexpr code. However, there’s still a key limitation: you can only use these containers in constexpr functions — not as top-level constexpr objects. That means you can't declare a constexpr std::vector or std::string at global scope and use it later in runtime without overhead for initialization. The language still doesn’t fully support top-level dynamic containers in constant expressions. In this talk, I’ll explore the current state of constant evaluation in modern C++, with a special focus on dynamic memory allocation in constexpr contexts. I’ll walk through the limitations in C++20 and show how you can go beyond them by implementing a custom allocator that enables truly compile-time std::vector, std::string, and other STL containers, which will become fully supported as constexpr in future standards, thus opening the door to more powerful and flexible compile-time programming. --- Slides: https://github.com/CppCon/CppCon2025/... Work at Hudson River Trading (HRT): https://tinyurl.com/safxfctf --- Sergey Dobychin Sergey worked in systems programming at Kaspersky Lab. Currently, he is developing desktop applications in C++. --- CppCon is the annual, week-long face-to-face gathering for the entire C++ community. The conference is organized by the C++ community for the community. You will enjoy inspirational talks and a friendly atmosphere designed to help attendees learn from each other, meet interesting people, and generally have a stimulating experience. Taking place this year in Aurora, Colorado, near the Denver airport, and including multiple diverse tracks, the conference will appeal to anyone from C++ novices to experts. Annual CppCon Conference - https://www.cppcon.org   / cppcon   https://x.com/cppcon   / cppconference     / cppcon   https://mastodon.social/@CppCon --- Videos Filmed & Edited by Bash Films: http://www.BashFilms.com YouTube Channel Managed by Digital Medium Ltd: https://events.digital-medium.co.uk --- #cpp #cplusplus #cppcon #cppprogramming #cplusplusprogramming #softwaredevelopment #softwareengineering #coding #code #computerscience #technology #technews #programming #programmer