C++ - Reddit

Recursion

Recursion is when you explain recursion using recursion.

#recursion #programming

https://redd.it/1ph7bdy
@r_cpp

Why everyone hates on C/C++ source generation?

It allows me to do magical reflection-related things in both C and C++

* it's faster than in-language metaprogramming (see zig's metaprog for example, slows down hugely the compiler) (and codegen is faster because the generator can be written in C itself and run natively with -O3 instead of being interpreted by the language's metaprogramming vm, plus it can be easily be executed manually only when needed instead of at each compilation like how it happens with in language metaprog.).

* it's easier to debug, you can print stuff during the codegen, but also insert text in the output file

* it's easier to read, write and maintain, usually procedural meta programming in other languages can get very "mechanical" looking, it almost seems like you are writing a piece of the compiler (for example

pub fn Vec(comptime T: type) type {
const fields = _std.builtin.Type.StructField{
.{ .name = "x", .type = T, .defaultvalue = null, .iscomptime = false, .alignment = 0 },
.{ .name = "y", .type = T, .defaultvalue = null, .iscomptime = false, .alignment = 0 },
.{ .name = "z", .type = T, .defaultvalue = null, .iscomptime = false, .alignment = 0 },
.{ .name = "w", .type = T, .defaultvalue = null, .iscomptime = false, .alignment = 0 },
};
return @Type(.{ .Struct = .{
.layout = .auto,
.fields = fields0..,
.decls = &.{},
.istuple = false,
}});
}

versus sourcegen script that simply says "struct {name} ..."

\* it's the only way to do stuff like SOA for now.. and c++26 reflection looks awful (and super flow)

However I made a post about it on both r/CProgramming and r/cpp and everyone hated on it

https://redd.it/1pgoc4y
@r_cpp

BEEP-8 – compile C++20 to a tiny ARM ROM and run it instantly in a browser

I’ve been working on a small side project called BEEP-8 and thought some C++ folks might find it interesting.

The idea is:

* you write C++20 (subset) against a small SDK
* cross-compile it to a ROM image for a tiny ARM-based “console”
* open a URL, point it at the ROM, and it runs immediately in your browser on PC or phone

No native install, no WASM glue – the browser is just hosting an emulator for a fixed virtual machine.

What the target looks like

* CPU: software ARMv4-ish core, integer-only, fixed 4 MHz “virtual clock”
* Memory: 1 MB RAM, 1 MB ROM
* Video: simple 8/16-bit-style VDP (tilemaps, sprites, 16-colour PICO-8-compatible palette)
* Audio: small tone/noise APU
* Input: buttons plus touch-friendly controls so it works on phones as well

From user code you never touch JS or WebGL; it just looks like a small C++ API plus some memory-mapped registers.

Toolchain / workflow

1. `git clone` [`https://github.com/beep8/beep8-sdk.git`](https://github.com/beep8/beep8-sdk.git)
* The repo includes a preconfigured GNU Arm GCC cross-compiler in-tree, so there’s no separate compiler install.
2. Write code in C or C++20 (integer-only environment) using the SDK headers.
3. Run `make` to build a `.b8` ROM for the virtual ARM machine.
4. Open [`https://beep8.org`](https://beep8.org) (or your own self-hosted copy), select the ROM, and it boots and runs in the browser at 60 fps.

Links

* Live console + sample games/demos (runs directly in the browser): [https://beep8.org](https://beep8.org)

SDK, toolchain, and source (MIT-licensed):
[https://github.com/beep8/beep8-sdk](https://github.com/beep8/beep8-sdk)

I’m curious what the C++ community thinks about this kind of target:

* Would you consider it a useful little playground for teaching C/C++ or for jams / prototypes?
* Any obvious changes you’d make to the API or build flow to make it nicer for C++ developers?
* If you were writing a small C++ library or demo for a 4 MHz ARM with 1 MB RAM, what would you build first?

Happy to answer questions or share more details about the toolchain and runtime if anyone’s interested.

https://redd.it/1pgjqdl
@r_cpp

Leadwerks Live Developer Chat 12/6/25
https://www.youtube.com/watch?v=iBb-3Jpy9Zw

https://redd.it/1pg2z77
@r_cpp

The worst programming language of all time

I didn't see it posted here yet. A 2 hour rant about C++

https://youtu.be/7fGB-hjc2Gc

"biggest takeaway from video is that somehow every single C++ feature has its own 400 page book dedicated exclusively to it"

It's hard to disagree with that comment.


https://redd.it/1pfx7zz
@r_cpp

Unable to job switch

Is anybody facing the same issue as me, not getting shortlisted anywhere. I am not sure what to do. I see my friends switching companies getting paid higher, they are coming from .net, python background. I personally feel that C++ jobs are getting reduced.

Although I am quite good at work still not able to find a better place for me that values my skills.

I am C++ dev having decent knowledge of Qt/QML.
Please share your thoughts.

https://redd.it/1pfw4hl
@r_cpp

Division — Matt Godbolt’s blog
https://xania.org/202512/06-dividing-to-conquer?utm_source=feed&utm_medium=rss

https://redd.it/1pftyw9
@r_cpp

Where is std::optional<T&&>???

10 years ago we've got std::optional<T>. Nice. But no std::optional<T&>... Finally, we are getting std::optional<T&> now (see beman project implementation) but NO std::optional<T&&>...

DO we really need another 10 years to figure out how std::optional<T&&> should work? Is it yet another super-debatable topic? This is ridiculous. You just cannot deliver features with this pace nowadays...

Why not just make std::optional<T&&> just like std::optional<T&> (keep rebind behavior, which is OBVIOUSLY is the only sane approach, why did we spent 10 years on that?) but it returns T&& while you're dereferencing it?

https://redd.it/1pfk0ox
@r_cpp

Anyone else struggling with super slow CI builds lately?

Our CI pipeline has gotten ridiculously slow over the past few months. What used to be 5–10 minutes is now creeping toward 30+, and it’s blocking merges and killing our turnaround time. We’ve cleaned up configs, optimized a few modules, and even bumped our runners, but the performance bump didn’t last long.

Before we start rewriting half the build system, I figured I’d ask: is anyone using something that actually speeds up CI builds in a noticeable way?

https://redd.it/1pf7jwe
@r_cpp

I built a Cargo-like package manager for C++ because I was sick of build system nonsense
https://github.com/Ammar-Alnagar/Cellion

https://redd.it/1pf33co
@r_cpp

HPX Tutorials: Algorithms
https://www.youtube.com/watch?v=AnjEpOn78q8

https://redd.it/1pf09ap
@r_cpp

Exploring a local-first C++ runtime

I’m experimenting with a lightweight C++20 runtime focused on offline-first behavior, async HTTP, WebSockets, and optional P2P communication.
Still early, but I’m curious how others in the C++ world approach routing efficiency and local-first resilience in unstable network environments.

https://redd.it/1peswwz
@r_cpp

Exploring an offline-first and P2P-oriented runtime design in C++20

I’ve been exploring some runtime design ideas in C++20, mostly around problems that appear in unreliable or unstable network environments.

The main concepts I’m experimenting with are:

offline-first execution (local-first state, fallback mode)
P2P communication between nodes
lightweight async HTTP handling
WebSocket-based messaging
a small middleware pipeline
a modular runtime structure instead of a large monolithic framework

I’m mostly curious about whether others in the C++ community have experimented with similar approaches (local-first systems, edge runtimes, distributed execution without strong cloud dependence).

If anyone has insights, prior work, design critiques, or papers worth reading, I would be glad to learn from them.

https://redd.it/1peppj9
@r_cpp

Introducing asyncio - a new open-source C++23 coroutine network framework

https://github.com/Hackerl/asyncio

asyncio is a coroutine-based networking framework built on top of libuv. Developed using C++23, it supports Linux, Windows, Android, and macOS, making it compatible with four major platforms.

It is far from being just a toy — it is production-ready code. At my company, software built on top of asyncio is already running on tens of thousands of employee office PCs (Windows/macOS), and Linux servers in production environments are gradually adopting it.

Key Features of asyncio:
- Simple and elegant code: The codebase is designed to be clean and compact.
- Flexible and graceful sub-task management: Manage subtasks effectively and with finesse.
- User-friendly APIs: Borrowed design inspiration from multiple languages, making the APIs intuitive and easy to use.
- Well-designed interfaces: Ensures seamless interaction and borrowing ideas from numerous programming paradigms.
- Straightforward task cancellation: Task cancellation is easy and direct.
- Effortless integration with synchronous code: Integration with threads or thread pools is straightforward and smooth.

https://redd.it/1pep8ie
@r_cpp

Time in C++: Understanding std::chrono::steady_clock
https://www.sandordargo.com/blog/2025/12/03/clocks-part-3-steady_clock

https://redd.it/1pdw276
@r_cpp

C++ Enum Class and Error Codes, part 3 · Mathieu Ropert
https://mropert.github.io/2025/12/03/enum_class_error_codes_part3/

https://redd.it/1pdvtuf
@r_cpp

New Learning Path at Qt Academy | Creating Qt Quick User Interfaces
http://qt.io/academy/course-catalog?#creating-qt-quick-user-interfaces

https://redd.it/1pdvgc0
@r_cpp

C++ Podcasts & Conference Talks (week 49, 2025)

Hi r/cpp! Welcome to another post in this series brought to you by Tech Talks Weekly. Below are all the C++ conference talks and podcasts published in the last 7 days.

1. **"How To Build Robust C++ Inter-Process Queues - Jody Hagins - CppCon 2025"** ⸱ +6k views ⸱ 26 Nov 2025 ⸱ 01h 03m 05s
2. **"Cutting C++ Exception Time by +90%? - Khalil Estell - CppCon 2025"** ⸱ +6k views ⸱ 28 Nov 2025 ⸱ 01h 05m 10s
3. **"Back to Basics: Master C++ Friendship - Mateusz Pusz - CppCon 2025"** ⸱ +2k views ⸱ 27 Nov 2025 ⸱ 00h 56m 53s
4. **"Optimize Automatic Differentiation Performance in C++ - Steve Bronder - CppCon 2025"** ⸱ +1k views ⸱ 01 Dec 2025 ⸱ 00h 59m 59s
5. **"Is Your C++ Code Leaking Memory? Discover the Power of Ownership-Aware Profiling"** ⸱ +1k views ⸱ 02 Dec 2025 ⸱ 00h 52m 02s tldw: -
6. **"Binary Parsing - C++23 Style! - Hari Prasad Manoharan - Meeting C++ 2025"** ⸱ +700 views ⸱ 26 Nov 2025 ⸱ 00h 46m 27s
7. **"PetriNet Studio - Architecting a SaaS Simulator in Modern C++ - Gabriel Valenzuela - Meeting C++2025"** ⸱ +300 views ⸱ 28 Nov 2025 ⸱ 00h 33m 11s

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 +7,400 Software Engineers who stopped scrolling through messy YT subscriptions/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/1pdtuc7
@r_cpp

A distributed mkcert-like tool written in C++

Make your development environment fully TLS-enabled — regardless of whether you access it from localhost, remote SSH, or WSL, and whether you use a browser or curl. Everything should run over HTTPS without any security warnings.

Project URL: https://github.com/coderealm-atlas/cert-ctrl

Compiles on Linux, Windows, macOS, and FreeBSD. Any feedback is welcome.

https://redd.it/1pdkvh9
@r_cpp

Structured iteration (The C++ way)
https://thecppway.com/posts/structured_iteration/

https://redd.it/1pdkki3
@r_cpp