of Professional C++, 2nd, 3rd, 4th, and 5th Edition  Co-author of C++ Standard Library Quick Reference& C++17 Standard Library Quick Reference  Founder of the Belgian C++ Users Group (BeCPP) C++204 Character Escapes  Trim Whitespace Before Line Splicing  C++23 Standard Library  String Formatting Improvements  Standard Library Modules  std::flat_(multi)map / std::flat_(multi)set  std::mdspan d_overwrite()  Monadic Operations for std::optional  Stacktrace Library  Changes to Ranges Library  Changes to Views Library  std::expected  std::move_only_function<>  std::spanstream 

Edition  5th Edition (C++20) coming later this year  Co-author of C++ Standard Library Quick Reference& C++17 Standard Library Quick Reference  Founder of the Belgian C++ Users Group (BeCPP)3 C++20 2020, the C++20 standard passed ISO voting, expected to be formally published by the end of 2020.4 Agenda  Modules  Ranges  Coroutines  Concepts  Lambda Expression Changes  [=, this] as in Lambda Captures  constexpr Changes  virtual functions  union, try/catch, dynamic_cast, typeid  allocations  constexpr string & vector  Concurrency Changes  Atomic Smart Pointers  Joining

IANA time zone database. • This functionality requires several new types to be added to the library: • tzdb • tzdb_list • time_zone • zoned_time • time_zone_link • ambiguous_local_time • nonexistent_local_time 2:00am. At this time, clocks were turned backward 1 hour to Sunday November 6, 2016 at 1:00am standard time instead. So, the time_point Nov 6, 2016 1:30am essentially occurred twice during that at 2:00am. At this time, clocks were turned forward 1 hour to Sunday March 13, 2016 at 3:00am standard time instead. So, the time_point March 13, 2016 2:30am did not exist during that early morning

语句里，从而只有某些选项开启才启用某语言之类的 设置 C++ 标准： CMAKE_CXX_STANDARD 变量 • CMAKE_CXX_STANDARD 是一个整数，表示要用的 C++ 标准。 • 比如需要 C++17 那就设为 17 ，需要 C++23 就设为 23 。 • CMAKE_CXX_STANDARD_REQUIRED 是 BOOL 类型，可以为 ON 或 OFF ，默认 OFF ON 则发现不支持报错，更安 全。 https://crascit.com/2015/03/28/enabling-cxx11-in-cmake/ 设置 C++ 标准： CMAKE_CXX_STANDARD 变量 • CMAKE_CXX_EXTENSIONS 也是 BOOL 类型，默认为 ON 。设为 ON 表示启用 GCC 特有的一些扩展功能； OFF 则关闭 GCC 的扩展功能，只使用标准的 的扩展功能，只使用标准的 C++ 。 • 要兼容其他编译器（如 MSVC ）的项目，都会设为 OFF 防止不小心用了 GCC 才有的 特性。 • 此外，最好是在 project 指令前设置 CMAKE_CXX_STANDARD 这一系列变量，这样 CMake 可以在 project 函数里对编译器进行一些检测，看看他能不能支持 C++17 的特 性。 https://crascit.com/2015/03/2

of Professional C++, 2nd, 3rd, 4th, and 5th Edition  Co-author of C++ Standard Library Quick Reference& C++17 Standard Library Quick Reference  Founder of the Belgian C++ Users Group (BeCPP) C++203 numbers at compile time  Always normalized representation  Needed for durations in the library6 Compile-Time Rational Numbers  Define a rational number: using r1 = ratio<1, 60>; // Represents duration>>;16 Durations – Predefined & Literals  Standard user-defined duration literals:  h, min, s, ms, us, and ns  Require any of the following using

Overview • What's happened in the last year • Part 1: C++20 STL Features • Everything here is Standard, except as noted • Part 2: GitHub Development • For contributors and observers3 Overview Part P1065R2 constexpr INVOKE (GH-703, AdamBucior) • Work in progress (mnatsuhara): • GH-37 P0784R7 Library Support For More constexpr Containers • GH-43 P0980R1 constexpr string • GH-45 P1004R2 constexpr track all remaining C++20 features • GH-39 P0896R4 • LWG issues track bugfixes in the Standard itself • GH-333 LWG-3070 path::lexically_relative • bug, performance, throughput, enhancement

reference count • Used by Folly (Facebook open-source library, used in production), • Used by JustThreads (Anthony Williams’ commercial concurrency library), • Anthony Williams also has a free, simplified nullptr checks to save space. atomic> What happens when a concurrent operation changes the pointer to a different shared_ptr?29 Daniel Anderson -- danielanderson.net Solution #2:

GridLayout. Loops • Beware of function and memory allocations inside of loops. You see this as a standard pattern. function loopFunction () { var val = 0; for (var i=0;i<100000;i++) { doSomething( code that can’t be optimized • debugger; statement. • Polymorphic functions Beware of Object changes! Questions A little about me • Developer of the NativeScript.rocks sites: • > 20 years doing programming

basic_string and basic_string_view • Other small features 🕙 Coming next for C++23 • STL • Standard library modules • Coroutines 💡 C++98* * with /permissive- 💡 C++11 💡 C++14 💡 C++17 💡 C++20* *awaiting Team Productivity Simplify C++ dependency management with . vcpkg Open-source library manager for Windows, Linux, and macOS 1700+ popular open-source libraries available for installation Create your own private library catalog for use within vcpkg; great for internal, closed-source 3rd party libraries and community repositories 🔢 Versioning Choose which library versions you want (works

贴合 ISO GQL Standard • Incorporate by reference specifications from SQL/Framework and SQL/Foundation • Capabilities needed by both SQL/PGQ (Property Graph Queries in SQL) and the GQL standard • GQL Specific comment resolution started •2023-06 – DIS (Draft International Standard) Ballot starts •2023-11 – DIS ballot ends •2024-04 – International Standard 类 SQL 语言，简单易用，面向分析师友好 查询引擎：计算请求执行流程 Cypher AST Unresolved 20+ 个 GNN 算法 • 支持同构图 / 异构图 / 属性图 客户的信任 • 上线某银行反欺诈场景 业务效果提升 10%+ 灵活易用的开发平台 • AtlasML Python Library • 集成 Jupyter Notebook 超参数自动优化 • 支持超参数自动调优，解放算 法科学家生产力，避免繁杂的 手动调参 海致图神经网络平台特点 Rust 语言特性助力构建高性能图数据库