Pseudo Reflection in C++20
I discovered constexpr member pointers somewhere when looking at c++20. You can use them as compile time annotations to enable full reflection in c++20.
I got tired of playing with BOOST and nholman and wanted a better solution to reflection and had a lot of fun doing this.
Your mileage may vary
https://github.com/johnagrillo/meta\_h/tree/main
https://redd.it/1pnm5a3
@r_cpp
I discovered constexpr member pointers somewhere when looking at c++20. You can use them as compile time annotations to enable full reflection in c++20.
I got tired of playing with BOOST and nholman and wanted a better solution to reflection and had a lot of fun doing this.
Your mileage may vary
https://github.com/johnagrillo/meta\_h/tree/main
https://redd.it/1pnm5a3
@r_cpp
GitHub
GitHub - johnagrillo/meta_h
Contribute to johnagrillo/meta_h development by creating an account on GitHub.
Writing a blatant Telegram clone using Qt, QML and Rust. And C++.
https://kemble.net/blog/provoke/
https://redd.it/1po0t2s
@r_cpp
https://kemble.net/blog/provoke/
https://redd.it/1po0t2s
@r_cpp
Kemble Software
Writing a blatant Telegram clone using Qt, QML and Rust. And C++.
This was a fun project for a couple of days, but I will probably shelve it for now so I can continue what I was already working on before. Read on to follow along with my journey.
Spoilers: I didn’t get very far.
Spoilers: I didn’t get very far.
Possible GCC reflection error
Playing with GCC I got a situation like this:
#include <algorithm>
#include <array>
#include <print>
#include <meta>
consteval auto Name(const int integer){
return std::meta::displaystringof(^^integer);
}
consteval auto Name(const std::meta::info meta){
return std::meta::displaystringof(meta);
}
// <source>:21:28: error: call to consteval function 'Name(^^int)' is not a constant expression
// 17 | std::println("{}", Name(^^int));
// | ~~~~^~~~~~~
// But removing const fix it!! (works in Clang P2996)
int main(){
std::println("{}", Name(3));
std::println("{}", Name(^^int));
return 0;
}
I think that this is not the expected behaviour, but is it a known bug to be patched?
https://redd.it/1po9oz2
@r_cpp
Playing with GCC I got a situation like this:
#include <algorithm>
#include <array>
#include <print>
#include <meta>
consteval auto Name(const int integer){
return std::meta::displaystringof(^^integer);
}
consteval auto Name(const std::meta::info meta){
return std::meta::displaystringof(meta);
}
// <source>:21:28: error: call to consteval function 'Name(^^int)' is not a constant expression
// 17 | std::println("{}", Name(^^int));
// | ~~~~^~~~~~~
// But removing const fix it!! (works in Clang P2996)
int main(){
std::println("{}", Name(3));
std::println("{}", Name(^^int));
return 0;
}
I think that this is not the expected behaviour, but is it a known bug to be patched?
https://redd.it/1po9oz2
@r_cpp
Reddit
From the cpp community on Reddit
Explore this post and more from the cpp community
Use GWP-ASan to detect exploits in production environments
https://blog.trailofbits.com/2025/12/16/use-gwp-asan-to-detect-exploits-in-production-environments/
https://redd.it/1pod1jh
@r_cpp
https://blog.trailofbits.com/2025/12/16/use-gwp-asan-to-detect-exploits-in-production-environments/
https://redd.it/1pod1jh
@r_cpp
The Trail of Bits Blog
Use GWP-ASan to detect exploits in production environments
GWP-ASan is a sampling-based memory error detection tool that catches critical bugs like use-after-free and buffer overflows in production environments with near-zero performance overhead, unlike AddressSanitizer which is too resource-intensive for deployment.
Do C++ developers exist?
Howdy folks! 🤠
I’ve been running an open-source project that turns images into colour-by-number templates. The JS side of things is doing great and I’ve got contributors for that, and they’re awesome.
Getting someone to touch the C++ core is like trying to find a unicorn. Seriously, it’s like C++ is the Black Plague to these people.🧟♂️ Everyone wants to work on the fun JS stuff, the frontend & React Hook WebAssembly bridge… but when it comes to the heavy-lifting C++, suddenly it’s “too hard” or “nah, I’ll pass.”
I get it, C++ can be a beast, but this is literally the heart of the project. Without it, none of the clustering or image processing magic even works. It’s like asking someone to play Jenga with bricks instead of sticks: still fun, but way more painful!
So here I am, ranting to the void. You're my last hope. Help me find the only other C++ developers on this earth.😁
If you know of someone who secretly enjoys fighting with C++ memory management and optimization, you are my hero. The JS folks are doing great, but we need some brave souls to dive into the C++ trenches with me so we can help the JS guys continue enjoying life.
Does anyone else feel this pain in OSS projects? Or am I just cursed to be the only one hunting for C++ contributors forever?
https://redd.it/1pofyma
@r_cpp
Howdy folks! 🤠
I’ve been running an open-source project that turns images into colour-by-number templates. The JS side of things is doing great and I’ve got contributors for that, and they’re awesome.
Getting someone to touch the C++ core is like trying to find a unicorn. Seriously, it’s like C++ is the Black Plague to these people.🧟♂️ Everyone wants to work on the fun JS stuff, the frontend & React Hook WebAssembly bridge… but when it comes to the heavy-lifting C++, suddenly it’s “too hard” or “nah, I’ll pass.”
I get it, C++ can be a beast, but this is literally the heart of the project. Without it, none of the clustering or image processing magic even works. It’s like asking someone to play Jenga with bricks instead of sticks: still fun, but way more painful!
So here I am, ranting to the void. You're my last hope. Help me find the only other C++ developers on this earth.😁
If you know of someone who secretly enjoys fighting with C++ memory management and optimization, you are my hero. The JS folks are doing great, but we need some brave souls to dive into the C++ trenches with me so we can help the JS guys continue enjoying life.
Does anyone else feel this pain in OSS projects? Or am I just cursed to be the only one hunting for C++ contributors forever?
https://redd.it/1pofyma
@r_cpp
Reddit
From the cpp community on Reddit
Explore this post and more from the cpp community
Using std::generator in practice - Nicolai Josuttis - Meeting C++ 2025
https://www.youtube.com/watch?v=Qpj9fVOoVAk
https://redd.it/1poh9n6
@r_cpp
https://www.youtube.com/watch?v=Qpj9fVOoVAk
https://redd.it/1poh9n6
@r_cpp
YouTube
C++23: using std::generator in practice - Nicolai Josuttis - Meeting C++ 2025
An introduction into std::generator in C++23 by Nico Josuttis at Meeting C++ 2025
Slides: https://slides.meetingcpp.com
C++20 introduced coroutines, which are functions that can be subspended and later resumed (in the same or a different context). As a consequence…
Slides: https://slides.meetingcpp.com
C++20 introduced coroutines, which are functions that can be subspended and later resumed (in the same or a different context). As a consequence…
C++ Podcasts & Conference Talks (week 51, 2025)
Hi r/cpp! Welcome to another post in this series brought to you by Tech Talks Weekly. Below, you'll find all the C++ conference talks and podcasts published in the last 7 days:
# 📺 Conference talks
# CppCon 2025
1. **"Crafting the Code You Don’t Write: Sculpting Software in an AI World - Daisy Hollman - CppCon 2025"** ⸱ +5k views ⸱ 12 Dec 2025 ⸱ 01h 38m 50s
2. **"Can C++ Data Oriented Design Be ONE MILLION Times Faster? - Andrew Drakeford"** ⸱ +5k views ⸱ 10 Dec 2025 ⸱ 00h 53m 30s
3. **"The Declarative Programming SECRETS to More Readable C++ - Richard Powell"** ⸱ +4k views ⸱ 11 Dec 2025 ⸱ 00h 58m 34s
4. **"What's New for C++ in VS Code: CMake Improvements and GitHub Copilot Agents - Alexandra Kemper"** ⸱ +1k views ⸱ 15 Dec 2025 ⸱ 01h 01m 02s
5. **"Can Modern C++ SPEED UP Your Bundle Adjustment Pipeline? - Vishnu Sudheer Menon"** ⸱ +600 views ⸱ 16 Dec 2025 ⸱ 00h 58m 11s
# Meeting C++ 2025
1. **"Start teaching C++ (to beginners!) - Hannah Lenk - Meeting C++ 2025 lighning talks"** ⸱ +1k views ⸱ 11 Dec 2025 ⸱ 00h 11m 06s
2. **"C++23: using std::generator in practice - Nicolai Josuttis - Meeting C++ 2025"** ⸱ +800 views ⸱ 15 Dec 2025 ⸱ 01h 01m 30s
# PyData Paris 2025
1. **"Johan Mabille & Anutosh Bhat - xeus-cpp, the new C++ kernel for Jupyter."** ⸱ <100 views ⸱ 16 Dec 2025 ⸱ 00h 30m 02s
This post is an excerpt from the latest issue of ***Tech Talks Weekly*** which is a free weekly email with all the recently published Software Engineering podcasts and conference talks. Currently subscribed by +7,500 Software Engineers who stopped scrolling through messy YT subnoscriptions/RSS feeds and reduced FOMO. Consider subscribing if this sounds useful: *https://www.techtalksweekly.io/*
Let me know what you think. Thank you!
https://redd.it/1pp3moi
@r_cpp
Hi r/cpp! Welcome to another post in this series brought to you by Tech Talks Weekly. Below, you'll find all the C++ conference talks and podcasts published in the last 7 days:
# 📺 Conference talks
# CppCon 2025
1. **"Crafting the Code You Don’t Write: Sculpting Software in an AI World - Daisy Hollman - CppCon 2025"** ⸱ +5k views ⸱ 12 Dec 2025 ⸱ 01h 38m 50s
2. **"Can C++ Data Oriented Design Be ONE MILLION Times Faster? - Andrew Drakeford"** ⸱ +5k views ⸱ 10 Dec 2025 ⸱ 00h 53m 30s
3. **"The Declarative Programming SECRETS to More Readable C++ - Richard Powell"** ⸱ +4k views ⸱ 11 Dec 2025 ⸱ 00h 58m 34s
4. **"What's New for C++ in VS Code: CMake Improvements and GitHub Copilot Agents - Alexandra Kemper"** ⸱ +1k views ⸱ 15 Dec 2025 ⸱ 01h 01m 02s
5. **"Can Modern C++ SPEED UP Your Bundle Adjustment Pipeline? - Vishnu Sudheer Menon"** ⸱ +600 views ⸱ 16 Dec 2025 ⸱ 00h 58m 11s
# Meeting C++ 2025
1. **"Start teaching C++ (to beginners!) - Hannah Lenk - Meeting C++ 2025 lighning talks"** ⸱ +1k views ⸱ 11 Dec 2025 ⸱ 00h 11m 06s
2. **"C++23: using std::generator in practice - Nicolai Josuttis - Meeting C++ 2025"** ⸱ +800 views ⸱ 15 Dec 2025 ⸱ 01h 01m 30s
# PyData Paris 2025
1. **"Johan Mabille & Anutosh Bhat - xeus-cpp, the new C++ kernel for Jupyter."** ⸱ <100 views ⸱ 16 Dec 2025 ⸱ 00h 30m 02s
This post is an excerpt from the latest issue of ***Tech Talks Weekly*** which is a free weekly email with all the recently published Software Engineering podcasts and conference talks. Currently subscribed by +7,500 Software Engineers who stopped scrolling through messy YT subnoscriptions/RSS feeds and reduced FOMO. Consider subscribing if this sounds useful: *https://www.techtalksweekly.io/*
Let me know what you think. Thank you!
https://redd.it/1pp3moi
@r_cpp
www.techtalksweekly.io
Tech Talks Weekly | Substack
Join 7,200+ Software Engineers and Engineering Leaders who receive a free weekly email with all the recently published podcasts and conference talks. Stop scrolling through messy YT subnoscriptions. Stop FOMO. Easy to unsubscribe. No spam, ever. Click to read…
Can I Beat Clang’s Auto-Vectorizer on Apple Silicon? A SAXPY Case Study
https://medium.com/@samarth.colleges/can-i-beat-clangs-auto-vectorizer-on-apple-silicon-a-saxpy-case-study-3c3926b5bfe3
https://redd.it/1pp5dpd
@r_cpp
https://medium.com/@samarth.colleges/can-i-beat-clangs-auto-vectorizer-on-apple-silicon-a-saxpy-case-study-3c3926b5bfe3
https://redd.it/1pp5dpd
@r_cpp
Medium
Can I Beat Clang’s Auto-Vectorizer on Apple Silicon? A SAXPY Case Study
On modern CPUs, the “slow” part of your code often isn’t the math — it’s how you feed the math units. Compilers try to fix this with…
Performance Engineer or RL Engineer
Dear all, I have an experience in performance optimization. I have worked in this field for a few years. I also have experience in C++ for many years.
Now I got an offer in RL field in a big company. It is confident.
Experience in performance opens a lot of doors. I can work in many big-techs.
But ML is growing now. And LLM probably can remove doors for C++ engineers.
Should I change my direction? I'm 30 years old now.
UPD: RL is Reinforcement Learning
https://redd.it/1pp7sxm
@r_cpp
Dear all, I have an experience in performance optimization. I have worked in this field for a few years. I also have experience in C++ for many years.
Now I got an offer in RL field in a big company. It is confident.
Experience in performance opens a lot of doors. I can work in many big-techs.
But ML is growing now. And LLM probably can remove doors for C++ engineers.
Should I change my direction? I'm 30 years old now.
UPD: RL is Reinforcement Learning
https://redd.it/1pp7sxm
@r_cpp
Reddit
From the cpp community on Reddit
Explore this post and more from the cpp community
Hey all I want a suggestion
So i'm in a private college pursuing B.tech in CS. I am currently in 1st semester but i want to do competitive programming , can anyone experienced help me with a roadmap that will actually work and i won't be wasting my time. I'm currently doing pattern printing so i'm beginner in C++
https://redd.it/1pph4sc
@r_cpp
So i'm in a private college pursuing B.tech in CS. I am currently in 1st semester but i want to do competitive programming , can anyone experienced help me with a roadmap that will actually work and i won't be wasting my time. I'm currently doing pattern printing so i'm beginner in C++
https://redd.it/1pph4sc
@r_cpp
Reddit
From the cpp community on Reddit
Explore this post and more from the cpp community
MSVC Debugging: Solve Static Initialization Order Fiasco in C++
https://www.kdab.com/msvc-debugging-the-static-initialization-order/
https://redd.it/1ppnxf1
@r_cpp
https://www.kdab.com/msvc-debugging-the-static-initialization-order/
https://redd.it/1ppnxf1
@r_cpp
KDAB
MSVC Debugging Guide: Solve Static Initialization Order Fiasco in C++ | KDAB
Learn how to debug static initialization issues in MSVC. Understand constructor order, CRT startup, and how to trace crashes before main() in C++.
Strong Structured Concurrency: How to Avoid Lifetime Footguns in std::execution
https://blog.vito.nyc/posts/structured-concurrency-1/
https://redd.it/1ppsjwq
@r_cpp
https://blog.vito.nyc/posts/structured-concurrency-1/
https://redd.it/1ppsjwq
@r_cpp
blog.vito.nyc
Strong Structured Concurrency: How to Avoid Lifetime Footguns in std::execution
A denoscription of a common failure mode for C++ programs built on C++26 std::execution
std::ranges may not deliver the performance that you expect
https://lemire.me/blog/2025/10/05/stdranges-may-not-deliver-the-performance-that-you-expect/
https://redd.it/1pptoq2
@r_cpp
https://lemire.me/blog/2025/10/05/stdranges-may-not-deliver-the-performance-that-you-expect/
https://redd.it/1pptoq2
@r_cpp
Daniel Lemire's blog
std::ranges may not deliver the performance that you expect
Good engineers seek software code that is 'simple' in the sense that we can read and understand it quickly. But they they also look for highly performant code. For the last 20 years, we have been offering programmers the possibility to replace conventional…
Sorting Comparator function how they works internally ?
static bool cmp(int a, int b){
return tostring(a) + tostring(b) >
tostring(b) + tostring(a);
}
https://redd.it/1pqdtxp
@r_cpp
static bool cmp(int a, int b){
return tostring(a) + tostring(b) >
tostring(b) + tostring(a);
}
https://redd.it/1pqdtxp
@r_cpp
Reddit
From the cpp community on Reddit
Explore this post and more from the cpp community
Latest News From Upcoming C++ Conferences (2025-12-19)
OPEN CALL FOR SPEAKERS
CppCon Academy 2026 – CppCon Academy is asking for instructors to submit proposals for pre- and post-conference classes and/or workshops to be taught in conjunction with next year’s CppCon 2026.
Workshops can be online or onsite and interested instructors have until January 30th to submit their workshops. Find out more including how to submit your proposal at https://cppcon.org/cfp-for-2026-classes/
ACCU on Sea 2026 – Interested speakers have until January 11th to submit their talks which is scheduled to take place on 17th – 20th June. Find out more including how to submit your proposal at [https://accuconference.org/callforspeakers](https://accuconference.org/callforspeakers)
OTHER OPEN CALLS
(NEW) C++Online
(NEW) Call For Online Volunteers – Attend C++Online 2026 FOR FREE by becoming an online volunteer! Find out more including how to apply at [https://cpponline.uk/call-for-volunteers/](https://cpponline.uk/call-for-volunteers/)
(NEW) Call For Online Posters – Get a FREE ticket to C++Online 2026 by presenting an online poster in their virtual venue which can be on any C++ or C++ adjacent topic. Find out more and apply at https://cpponline.uk/posters
(NEW) Call For Open Content – Get a FREE ticket to C++Online 2026 by…
Presenting a talk, demo or workshop as open content at the start or end of each day of the event. Find out more and apply at https://cpponline.uk/call-for-open-content/
Running a meetup or host a social event like a pub quiz or a tetris tournament. Find out more and apply at [https://cpponline.uk/call-for-meetups/](https://cpponline.uk/call-for-meetups/)
If you run a meetup, then discounted entry will be given for other members of your meetup.
TICKETS AVAILABLE TO PURCHASE
The following conferences currently have tickets available to purchase
ACCU on Sea (15th – 20th June) – You can buy super early bird tickets at [https://accuconference.org/booking](https://accuconference.org/booking) with discounts available for ACCU members.
OTHER NEWS
(NEW) C++Online 2026 Announced (11th – 13th March) – The C++Online 2026 Conference has been announced and will run as an online only conference and will also include post-conference workshops (separate registration required). Find out more at https://cpponline.uk/announcing-cpponline-2026-11th-13th-march/
(NEW) C++Now 2026 Announced (4th – 8th May) – The C++Now 2026 Conference has been announced and will run as an in-person only conference in Aspen, Colorado. Find out more at [https://cppnow.org/announcements/2025/12/announcing-cppnow-2026/](https://cppnow.org/announcements/2025/12/announcing-cppnow-2026/)
C++Online 2026 Call For Reviews Open – The C++Online team are looking for people to review talks that were submitted to be considered for the C++ Online 2026 programme. Please visit https://speak.cpponline.uk/ and login or make an account to review the talks with reviews accepted until December 22nd.
https://redd.it/1pqpv7p
@r_cpp
OPEN CALL FOR SPEAKERS
CppCon Academy 2026 – CppCon Academy is asking for instructors to submit proposals for pre- and post-conference classes and/or workshops to be taught in conjunction with next year’s CppCon 2026.
Workshops can be online or onsite and interested instructors have until January 30th to submit their workshops. Find out more including how to submit your proposal at https://cppcon.org/cfp-for-2026-classes/
ACCU on Sea 2026 – Interested speakers have until January 11th to submit their talks which is scheduled to take place on 17th – 20th June. Find out more including how to submit your proposal at [https://accuconference.org/callforspeakers](https://accuconference.org/callforspeakers)
OTHER OPEN CALLS
(NEW) C++Online
(NEW) Call For Online Volunteers – Attend C++Online 2026 FOR FREE by becoming an online volunteer! Find out more including how to apply at [https://cpponline.uk/call-for-volunteers/](https://cpponline.uk/call-for-volunteers/)
(NEW) Call For Online Posters – Get a FREE ticket to C++Online 2026 by presenting an online poster in their virtual venue which can be on any C++ or C++ adjacent topic. Find out more and apply at https://cpponline.uk/posters
(NEW) Call For Open Content – Get a FREE ticket to C++Online 2026 by…
Presenting a talk, demo or workshop as open content at the start or end of each day of the event. Find out more and apply at https://cpponline.uk/call-for-open-content/
Running a meetup or host a social event like a pub quiz or a tetris tournament. Find out more and apply at [https://cpponline.uk/call-for-meetups/](https://cpponline.uk/call-for-meetups/)
If you run a meetup, then discounted entry will be given for other members of your meetup.
TICKETS AVAILABLE TO PURCHASE
The following conferences currently have tickets available to purchase
ACCU on Sea (15th – 20th June) – You can buy super early bird tickets at [https://accuconference.org/booking](https://accuconference.org/booking) with discounts available for ACCU members.
OTHER NEWS
(NEW) C++Online 2026 Announced (11th – 13th March) – The C++Online 2026 Conference has been announced and will run as an online only conference and will also include post-conference workshops (separate registration required). Find out more at https://cpponline.uk/announcing-cpponline-2026-11th-13th-march/
(NEW) C++Now 2026 Announced (4th – 8th May) – The C++Now 2026 Conference has been announced and will run as an in-person only conference in Aspen, Colorado. Find out more at [https://cppnow.org/announcements/2025/12/announcing-cppnow-2026/](https://cppnow.org/announcements/2025/12/announcing-cppnow-2026/)
C++Online 2026 Call For Reviews Open – The C++Online team are looking for people to review talks that were submitted to be considered for the C++ Online 2026 programme. Please visit https://speak.cpponline.uk/ and login or make an account to review the talks with reviews accepted until December 22nd.
https://redd.it/1pqpv7p
@r_cpp
Software and Safety - Anthony Williams - Keynote Meeting C++ 2025
https://www.youtube.com/watch?v=wKGkOmpUTH8
https://redd.it/1pqrm5r
@r_cpp
https://www.youtube.com/watch?v=wKGkOmpUTH8
https://redd.it/1pqrm5r
@r_cpp
YouTube
Software and Safety - Anthony Williams - Keynote Meeting C++ 2025
Anthony Williams Keynote on Software and Safety from Meeting C++ 2025
Software is everywhere, not only in the form of applications that we
use explicitly, but in everything from home appliances like toasters
and fridges, light switches, and heating controls…
Software is everywhere, not only in the form of applications that we
use explicitly, but in everything from home appliances like toasters
and fridges, light switches, and heating controls…