September 13-19, Aurora, CO, USA
October 25, Pavia, Italy
November 6-8, Berlin, Germany
November 3-8, Kona, HI, USA
By Adrien Hamelin | Feb 24, 2022 11:46 AM | Tags: c++20
Making things clearer.
Projections are Function Adaptors
by Barry Revzin
From the article:
There was a question recently on StackOverflow where a user was confused about the purpose of projections in a way that I think is fairly common...
By René Ferdinand Rivera Morell | Feb 24, 2022 10:57 AM | Tags: None
Should the C++ standard change to include its ecosystem?
Open letter for new C++ scope/charter
by René Ferdinand Rivera Morell
From the letter:
We are writing asking for consideration towards changes to the wording of the "ISO/IEC JTC1/SC22/WG21 STATEMENT OF SCOPE". Which is currently stated as:
Development and maintenance of ISO/IEC Standards, Technical Specifications, and Technical Reports related to the programming language C++.
Reddit discussion here.
By Adrien Hamelin | Feb 23, 2022 02:53 PM | Tags: None
What are your thoughts?
Design Patterns VS Design Principles: Visitor
by Jonathan Boccara
From the article:
In today’s episode of the series “Design Pattens VS Design Principles”, we’re focusing on the last behavioural design pattern: Visitor, and see how it relates to the High Cohesion design principle...
By Adrien Hamelin | Feb 23, 2022 02:50 PM | Tags: community
Will you participate?
More Information about my Mentoring Program "Fundamentals for C++ Professionals"
by Rainer Grimm
From the article:
One month ago, I presented "My Mentoring Program "Fundamentals for C++ Professionals". I'm overwhelmed by how my people want to participate in this first iteration of my mentoring program. What should I say? Today, I want to give you more details.
By Adrien Hamelin | Feb 23, 2022 02:48 PM | Tags: intermediate
Are you familiar with it?
SFINAE: Substitution Failure is not an Error | Top-Up C++ [C++ #02]
by WolfSound
Summary of the video:
In this video, we are presenting SFINAE: Substitution Failure is not an Error, a feature or a characteristic of C++ related to templates. “Substitution failure is not an error” means that if the compiler fails to specialize a template with a given template argument list, it does not issue an error. It does when it cannot find any suitable function/class to be called/instantiated (either due to a lack of suitably declared functions/classes or an error during instantiation).
By Administrator | Feb 22, 2022 08:23 AM | Tags: None
The 2022-02 mailing of new standards papers is now available.
| WG21 Number | Title | Author | Document Date | Mailing Date | Previous Version | Subgroup |
|---|---|---|---|---|---|---|
| N4903 | PL22.16/WG21 agenda: 7 February 2022, Virtual Meeting | John Spicer | 2022-01-24 | 2022-02 | All of WG21 | |
| N4904 | WG21 admin telecon meetings: 2022 summer and autumn (revision 1) | Herb Sutter | 2022-01-24 | 2022-02 | All of WG21 | |
| N4905 | WG21 2022-01 Admin telecon minutes | Nina Ranns | 2022-02-01 | 2022-02 | All of WG21 | |
| N4906 | Transactional Memory TS2 | Michael Wong | 2022-02-18 | 2022-02 | All of WG21 | |
| N4907 | WG21 2022-02 Virtual Meeting Minutes of Meeting | Nina Ranns | 2022-02-17 | 2022-02 | All of WG21 | |
| P0009R15 | MDSPAN | Christian Trott | 2022-02-14 | 2022-02 | P0009R14 | LWG Library |
| P0323R12 | std::expected | JF Bastien | 2022-02-21 | 2022-02 | P0323R11 | LWG Library |
| P0447R19 | Introduction of std::hive to the standard library | Matt Bentley | 2022-02-17 | 2022-02 | P0447R18 | SG14 Low Latency,LEWG Library Evolution,All of WG21 |
| P0561R6 | An RAII Interface for Deferred Reclamation | Geoffrey Romer | 2022-02-02 | 2022-02 | P0561R5 | LWG Library |
| P0792R7 | function_ref: a non-owning reference to a Callable | Vittorio Romeo | 2022-02-14 | 2022-02 | P0792R6 | LEWG Library Evolution,LWG Library |
| P0792R8 | function_ref: a non-owning reference to a Callable | Vittorio Romeo | 2022-02-16 | 2022-02 | P0792R7 | LEWG Library Evolution,LWG Library |
| P0957R5 | Proxy: A Polymorphic Programming Library | Mingxin Wang | 2022-02-14 | 2022-02 | P0957R4 | LEWGI SG18: LEWG Incubator |
| P1018R15 | C++ Language Evolution status pandemic edition 2022/01–2022/02 | JF Bastien | 2022-02-14 | 2022-02 | P1018R14 | EWG Evolution,All of WG21 |
| P1202R4 | Asymmetric Fences | David Goldblatt | 2022-02-14 | 2022-02 | P1202R3 | LEWG Library Evolution,LWG Library |
| P1223R3 | find_last | Zach Laine | 2022-02-14 | 2022-02 | P1223R2 | LEWG Library Evolution,LWG Library |
| P1478R7 | Byte-wise atomic memcpy | Hans Boehm | 2022-02-05 | 2022-02 | P1478R6 | LWG Library |
| P1664R7 | reconstructible_range - a concept for putting ranges back together | JeanHeyd Meneide | 2022-02-15 | 2022-02 | P1664R6 | SG9 Ranges,LEWG Library Evolution |
| P1774R6 | Portable assumptions | Timur Doumler | 2022-02-15 | 2022-02 | P1774R5 | CWG Core |
| P1839R3 | Accessing Object Representations | Krystian Stasiowski | 2022-02-18 | 2022-02 | P1839R2 | CWG Core |
| P1841R3 | Wording for Individually Specializable Numeric Traits | Walter E Brown | 2022-02-14 | 2022-02 | P1841R2 | LWG Library |
| P1885R10 | Naming Text Encodings to Demystify Them | Corentin Jabot | 2022-02-14 | 2022-02 | P1885R9 | LEWG Library Evolution |
| P2093R13 | Formatted output | Victor Zverovich | 2022-02-09 | 2022-02 | P2093R12 | LWG Library |
| P2214R2 | A Plan for C++23 Ranges | Barry Revzin | 2022-02-18 | 2022-02 | P2214R1 | LEWG Library Evolution |
| P2416R2 | Presentation of requirements in the standard library | Jens Maurer | 2022-02-14 | 2022-02 | P2416R1 | LWG Library |
| P2438R2 | std::string::substr() && | Federico Kircheis | 2022-02-04 | 2022-02 | P2438R1 | LWG Library |
| P2441R2 | views::join_with | Barry Revzin | 2022-01-28 | 2022-02 | P2441R1 | LEWG Library Evolution |
| P2446R2 | views::as_rvalue | Barry Revzin | 2022-02-14 | 2022-02 | P2446R1 | LEWG Library Evolution |
| P2448R2 | Relaxing some constexpr restrictions | Barry Revzin | 2022-01-27 | 2022-02 | P2448R1 | CWG Core |
| P2452R0 | 2021 October Library Evolution and Concurrency Polls on Networking and Executors | Bryce Adelstein Lelbach | 2022-02-15 | 2022-02 | LEWG Library Evolution | |
| P2453R0 | 2021 October Library Evolution Poll Outcomes | Bryce Adelstein Lelbach | 2022-02-15 | 2022-02 | SG4 Networking,LEWG Library Evolution | |
| P2458R1 | 2022 January Library Evolution Polls | Bryce Adelstein Lelbach | 2022-01-26 | 2022-02 | P2458R0 | LEWG Library Evolution |
| P2459R0 | 2022 January Library Evolution Poll Outcomes | Bryce Adelstein Lelbach | 2022-02-15 | 2022-02 | LEWG Library Evolution | |
| P2465R2 | Standard Library Modules std and std.compat | Stephan T. Lavavej | 2022-02-02 | 2022-02 | P2465R1 | CWG Core,LWG Library |
| P2467R1 | Support exclusive mode for fstreams | Jonathan Wakely | 2022-02-17 | 2022-02 | P2467R0 | LWG Library |
| P2472R1 | make function_ref more functional | Jarrad J. Waterloo | 2022-02-15 | 2022-02 | P2472R0 | LEWG Library Evolution |
| P2495R0 | Interfacing stringstreams with string_view | Michael Hava | 2022-02-13 | 2022-02 | LEWG Library Evolution | |
| P2502R1 | std::generator: Synchronous Coroutine Generator for Ranges | Casey Carter | 2022-01-25 | 2022-02 | P2502R0 | LEWG Library Evolution |
| P2505R1 | Monadic Functions for std::expected | Jeff Garland | 2022-02-15 | 2022-02 | P2505R0 | LEWG Library Evolution,LWG Library |
| P2506R0 | std::lazy: a coroutine for deferred execution | Casey Carter | 2022-02-02 | 2022-02 | LEWG Library Evolution | |
| P2513R1 | char8_t Compatibility and Portability Fix | JeanHeyd Meneide | 2022-02-14 | 2022-02 | P2513R0 | EWG Evolution |
| P2521R1 | Contract support -- Working Paper | Andrzej Krzemieński | 2022-02-15 | 2022-02 | P2521R0 | SG21 Contracts |
| P2528R0 | C/C++ Identifier Security using Unicode Standard Annex 39 | Reini Urban | 2022-01-22 | 2022-02 | SG16 Unicode,EWG Evolution,CWG Core | |
| P2529R0 | generator should have T&& reference_type | Mathias Stearn | 2022-01-25 | 2022-02 | LEWG Library Evolution | |
| P2530R0 | Why Hazard Pointers should be in C++26 | Maged Michael | 2022-02-14 | 2022-02 | SG1 Concurrency and Parallelism | |
| P2531R0 | C++ Standard Library Issues to be moved in Virtual Plenary, Feb. 2022 | Jonathan Wakely | 2022-01-31 | 2022-02 | All of WG21 | |
| P2532R0 | Removing exception_ptr from the Receiver Concepts | Eric Niebler | 2022-02-01 | 2022-02 | LEWG Library Evolution | |
| P2533R0 | Core Language Working Group "ready" Issues for the February, 2022 Meeting | William M. (Mike) Miller | 2022-02-21 | 2022-02 | All of WG21 | |
| P2534R0 | Slides: function_ref in the wild (P0792R7 presentation) | Zhihao Yuan | 2022-02-16 | 2022-02 | LEWG Library Evolution | |
| P2535R0 | Message fences | Olivier Giroux | 2022-02-02 | 2022-02 | SG1 Concurrency and Parallelism | |
| P2536R0 | Distributing C++ Module Libraries with dependencies json files. | Olga Arkhipova | 2022-02-03 | 2022-02 | SG15 Tooling | |
| P2537R0 | Relax va_start Requirements to Match C | JeanHeyd Meneide | 2022-02-14 | 2022-02 | LEWG Library Evolution | |
| P2538R0 | ADL-proof std::projected | Arthur O'Dwyer | 2022-02-15 | 2022-02 | LEWG Library Evolution,LWG Library | |
| P2540R0 | Empty Product for certain Views | Steve Downey | 2022-02-15 | 2022-02 | SG9 Ranges | |
| P2541R0 | Consider renaming remove_quals | Corentin Jabot | 2022-02-15 | 2022-02 | SG22 Compatability | |
| P2542R0 | views::concat | Hui Xie | 2022-02-18 | 2022-02 | SG9 Ranges,LEWG Library Evolution | |
| P2544R0 | C++ exceptions are becoming more and more problematic | Thomas Neumann | 2022-02-12 | 2022-02 | EWGI SG17: EWG Incubator | |
| P2545R0 | Why RCU Should be in C++26 | Paul E. McKenney | 2022-02-14 | 2022-02 | SG1 Concurrency and Parallelism,LEWG Library Evolution | |
| P2546R0 | Debugging Support | René Ferdinand Rivera Morell | 2022-02-14 | 2022-02 | SG15 Tooling,LEWG Library Evolution | |
| P2547R0 | Language support for customisable functions | Lewis Baker | 2022-02-15 | 2022-02 | EWG Evolution | |
| P2549R0 | std::unexpected should have error() as member accessor | Yihe Li | 2022-02-13 | 2022-02 | LEWGI SG18: LEWG Incubator,LEWG Library Evolution | |
| P2550R0 | ranges::copy should say output_iterator somewhere | Barry Revzin | 2022-02-16 | 2022-02 | LWG Library | |
| P2551R0 | Clarify intent of P1841 numeric traits | Matthias Kretz | 2022-02-14 | 2022-02 | LEWG Library Evolution | |
| P2552R0 | On the ignorability of standard attributes | Timur Doumler | 2022-02-16 | 2022-02 | EWG Evolution | |
| P2553R0 | Make mdspan size_type controllable | Christian Trott | 2022-02-14 | 2022-02 | LEWG Library Evolution | |
| P2554R0 | C-Array Interoperability of MDSpan | Christian Trott | 2022-02-14 | 2022-02 | LEWG Library Evolution | |
| P2555R0 | Naming improvements for std::execution | Jens Maurer | 2022-02-15 | 2022-02 | LEWG Library Evolution | |
| P2557R0 | WG21 2022-02 Virtual Meeting Record of Discussion | Nina Ranns | 2022-02-17 | 2022-02 | All of WG21 |
By Vittorio Romeo | Feb 18, 2022 12:22 PM | Tags: None
This article features an interview to the four authors of the newly released "Embracing Modern C++ Safely" book, motivating the surprising decision to analyze C++11 and C++14 in-depth in 2021, and discussing the contents and style of the publication.
Why 4 Bloomberg engineers wrote another C++ book
Tech At Bloomberg
From the article:
But why do we need yet another C++ book? After all, one of the book’s principal authors, John Lakos, has already written two. And why now? Why Bloomberg? Who is this for? But first, why modern C++? [...] The authors limited the book to features with which they have accumulated more than five years of experience. The current edition is an authoritative summary of C++11 and C++14 features, and future editions are planned to cover C++17 and C++20.
(Note that "Embracing Modern C++ Safely" is on sale (up to 55% off) until February 26.)
By Adrien Hamelin | Feb 16, 2022 09:56 AM | Tags: c++20
Many new possibilities.
constexpr and consteval Functions in C++20
by Rainer Grimm
From the article:
With C++20, constexpr became way more powerful. Additionally, we have consteval functions in C++20 that are quite similar to constexpr functions...
By Adrien Hamelin | Feb 16, 2022 09:50 AM | Tags: advanced
How did you solve it?
On finding the average of two unsigned integers without overflow
by Raymond Chen
From the article:
Finding the average of two unsigned integers, rounding toward zero, sounds easy:
unsigned average(unsigned a, unsigned b) { return (a + b) / 2; }However, this gives the wrong answer in the face of integer overflow: For example, if unsigned integers are 32 bits wide, then it says that average(0x80000000U, 0x80000000U) is zero...
By Adrien Hamelin | Feb 16, 2022 09:41 AM | Tags: c++17
Have you ever done that?
Technique: Compile Time Code Generation and Optimization
by Jonathan Müller
From the article:
C++ constexpr is really powerful. In this blog post, we’ll write a compiler that can parse a Brainfuck program given as string literal, and generate optimized assembly instructions that can then be executed at runtime. The best part: we neither have to actually generate assembly nor optimize anything ourselves! Instead we trick the compiler into doing all the hard work for us.
The same technique can be used whenever you want to specify some sort of “program” in a different way and translate it at runtime: regexes, routing tables, etc.
