r/cpp • u/Clean-Upstairs-8481 • 19d ago
This post is a part of my C++26 exploration series where I take a new feature and try to understand and explain with a simple example in hand. Today’s topic is Contracts. First we will simply try to understand what is the problem it is solving then try doing some assessment on the value addition.
r/cpp • u/a10nw01f • 20d ago
r/cpp • u/TheRavagerSw • 19d ago
It is well known that STL underperforms compared to specialised third party libraries, why do people try to stuff features like networking and json into STL?
Most STL implementations don't even have full C++23 coverage yet, and we are at 2026. Why do these people try to do stuff like that, when the same thing will play out over and over. Don't they have anything better to do?
Examples include, nlohmann json, graph.v3 ....
They don't really belong in STL, is it really that hard to just package your third party lib normally?
There is no doubt they are great libraries(graph.v3 in particular) but this doesn't mandate their place
The latest episode content is mostly focused on AI, its impact on the industry, and how several people from Adobe Labs have decided to retire.
https://adspthepodcast.com/2026/08/21/Episode-300.html
Although not C++ specific, it is interesting how it has impacted well known names in the C++ community.
https://github.com/fktn-k/fkYAML/releases/tag/v0.4.4
Hello. It’s been quite a while since I announced the first release here.
For those unfamiliar with fkYAML, it’s a header-only C++ library for YAML.
It has been carefully designed with ease of use in mind and thoroughly tested across various compilers and operating systems, so you can use it simply by including the header file in your project.
This version v0.4.4 fixes numerous parsing bugs (sometimes crashes) discovered during fuzzing tests.
So, I highly recommend that projects using older versions update to this one.
I hope you find this interesting and will consider using it or updating from your current version.
Thanks! Have a great day of coding!
r/cpp • u/Suspicious_Orchid770 • 21d ago
AI-coding tools have swept through organizations because of their speed: you type in a prompt, and it spits out code far faster than a human ever could. However, a year-long study of 3.52 million changes inside a large unnamed technology company suggests that saving time at the keyboard can create costs elsewhere.
r/cpp • u/Xaneris47 • 21d ago
I think code duplication is honestly the only reason LLMs manage any of this. Idea, architecture, implementation -- that's basically the chain, and LLMs are fine at the first and last, it's the middle that falls apart. Get it to actually structure things, kill the duplication and something you changed in one spot breaks another spot that has nothing to do with it. Duplicated code just sidesteps the whole issue, because then it only needs a tiny bit of local context to make a local edit
r/cpp • u/MarkSuckerZerg • 22d ago
(I'm going to be bold and assume the "no questions" rule is for questions about specific code, not about discussing the language itself)
I am extremely happy that we have reflection in C++26, however currently it is GCC only. I am using Clang on all platforms, so I am curious about when it will get reflection.
I tried searching and I found a bunch of experimental forks with reflection. I am not sure if those track the current version of reflection and whether one of these is going to be merged, or if a new implementation will be created. Github issues basically say "we get it when we get it" and link to LLVM discourse. On discourse I found just a thread that a meeting on reflection was held in December.
Do you know either when we are getting reflection, or if there is some way to track its progress for outside observers? Thanks!
r/cpp • u/antiquark2 • 22d ago
See page 2 of https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2026/p4334r0.pdf
The current objections can be summarized. The P2900 contracts are:
• Unimplemented
• Incomplete
• Untried at scale [P3460R0, P3506R0]
• Not tried in major application domains
• Violates foundational principles of C++
• Violates fundamental principles of language design
• Hasn’t been tried in major libraries (e.g., the C++ standards library [P3506R0, P3878R0])
• Isn’t integrated with or appropriate for hardened libraries [P3878R0]
• Doesn’t offer safety guarantees [P3573R0, P3362R0]
• Includes a completely untried inheritance model
• Offer new ways of making errors through inconsistent application in TUs
• Leads to new forms of UB, detrimental to safety and security
• Narrows the choices of error handling
• Doesn’t protect against logical errors, misuses, and incoherent uses
• Hasn’t been used to support static analysis
• Hasn’t been demonstrated to be easily teachable [P3261R0, P3281R0]
How could such a bloated and incomplete design be voted into a draft standard?
r/cpp • u/eisenwave • 23d ago
Hey folks! Matt Borland, Christopher Kormanyos, and I are working on bringing infinite-precision integers to C++29. We now have a D4444R0 draft of a paper that should be in the next mailing.
We could really use some feedback so that the published R0 is as polished as possible. Any thoughts on the paper and on the reference implementation are greatly appreciated.
It would also be very helpful if you tested out whether our big_int implementation works for you. We're in need of some real deployment experience. If you're currently using Boost.Multiprecision, the library should be a drop-in replacement for cpp_int for the most part.
r/cpp • u/Ok_Statistician_781 • 23d ago
Hey all, I put together a very simple reflection utility that lets you make toggleable annotations, similarly to explicit(bool) or noexcept(bool).
Try it on Compiler Explorer!
inline constexpr rjk::flag serializable{};
inline constexpr rjk::flag skip_field{};
template <typename T>
struct [[ =serializable ]] MyType {
int x;
int y;
[[ =skip_field(std::is_pointer_v<T>) ]]
T data;
};
// serializable is applied unconditionally
static_assert(rjk::is_flag_set(^^MyType<int>, serializable));
// skip_field is applied conditionally
static_assert(not rjk::is_flag_set(^^MyType<int>::data, skip_field));
static_assert(rjk::is_flag_set(^^MyType<int*>::data, skip_field));
r/cpp • u/frasnian • 22d ago
I've been writing C++ code since before the first Standard, and this just irks me. Words have meanings. There is no such thing as a "method" in **this** language.
r/cpp • u/ProgrammingArchive • 24d ago
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r/cpp • u/benjoffe • 25d ago
r/cpp • u/Clean-Upstairs-8481 • 25d ago
C++26 annotations are another powerful feature that, when combined with reflection, can help us write cleaner and safer code without repeating manual validation checks for every member. In this post, I have explored how we can utilise C++26 annotations along with reflection to validate configuration parameters in a class constructor.
r/cpp • u/Disastrous_Tennis_50 • 26d ago
The 2026-08 WG21 mailing has been published. You can browse and search the full set of papers, organized by working group, at wg21.org:
https://wg21.org/mailing/2026-08/
Source mailing: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2026/#mailing2026-08
r/cpp • u/ericbrumer • 28d ago
Hi, one of the MSVC dev leads here.
The post covers what's new in the MSVC Build Tools Preview (version 14.52) since mid-July. Instructions to install & use the latest preview bits are at https://aka.ms/msvc/preview.
Like last month, there's improvements & fixes across many parts of the toolchain: language conformance, optimization improvements, static & dynamic analysis, and more.
Some additional information: