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Day 3 of Advent of Compiler Optimisations! A while loop, recursion, direct addition—all compile to one instruction. The compiler sees the pattern beneath the code.

xania.org/202512/03-mo...
youtu.be/wHg9lYPMvvE

#AoCO2025

You can't fool the optimiser — Matt Godbolt’s blog

Pattern recognition can see through obfuscated code to find the right instruction

xania.org

December 3, 2025 at 12:00 PM

Reposted

meetingcpp.bsky.social

@meetingcpp.bsky.social

Our Most Treacherous Adversary - James McNellis - Meeting C++ 2025 lightning talks
www.youtube.com/watch?v=zC_u...
#cpp
#cplusplus

Our Most Treacherous Adversary - James McNellis - Meeting C++ 2025 lightning talks

YouTube video by Meeting Cpp

www.youtube.com

December 2, 2025 at 6:29 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

Addressing the adding situation
xania.org/202512/02-ad...
#cpp
#cplusplus

Addressing the adding situation — Matt Godbolt’s blog

We learn why adding on x86 isn't as obvious as you might think

xania.org

December 3, 2025 at 9:45 AM

meetingcpp.bsky.social

@meetingcpp.bsky.social

Time in C++: Understanding std::chrono::steady_clock
www.sandordargo.com/blog/2025/12...
#cpp
#cplusplus

Time in C++: Understanding std::chrono::steady_clock

In the previous articles, we explored what clocks are in general and took a closer look at std::chrono::system_clock, the one that represents the wall-clock or calendar time. Now let’s move to another...

www.sandordargo.com

December 3, 2025 at 8:57 AM

meetingcpp.bsky.social

@meetingcpp.bsky.social

#CppPollOfToday: Which C++17 library features are you using?
meetingcpp.com/mcpp/survey/...
#cplusplus
#cpp

Meeting C++ Community Survey

meetingcpp.com

December 2, 2025 at 11:05 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

C++23 Behind The Scenes: The Effort to Bring C++23 to RAD Studio Explained
blogs.embarcadero.com/c23-behind-t...
#cpp
#cplusplus

C++23 Behind The Scenes: The Effort to Bring C++23 to RAD Studio Explained

blogs.embarcadero.com

December 2, 2025 at 9:53 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

Our Most Treacherous Adversary - James McNellis - Meeting C++ 2025 lightning talks
www.youtube.com/watch?v=zC_u...
#cpp
#cplusplus

Our Most Treacherous Adversary - James McNellis - Meeting C++ 2025 lightning talks

YouTube video by Meeting Cpp

www.youtube.com

December 2, 2025 at 6:29 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

You got to wait 30 more minutes :D

December 2, 2025 at 4:47 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

Slicing makes you cry
marcofoco.com/blog/2025/12...
#cpp
#cplusplus

Slicing makes you cry – C++ explained to my dog

marcofoco.com

December 2, 2025 at 2:39 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

Meeting C++ is running a 24h++ event as a fundraiser for Meeting C++ on December 18th + 19th!
meetingcpp.com/mcpp/online/...
#cpp
#cplusplus

December 2, 2025 at 1:22 PM

Reposted

Steve Downey

@sdowney.org

Some c++ that puzzled me
sdowney.org/posts/substi...

I'm sure I knew this, but writing it down maybe I'll remember I knew this.

Substitution is Sometimes a Failure

Why are optional::transform and optional::and_then not constrained by invocable? 1. Optional "Monadic" Interface Monadic operations for std::optional transform is the c++ spelling for map or

sdowney.org

December 2, 2025 at 12:49 PM

Reposted

Tristan Brindle

@tristanbrindle.com

I might have overdone the sequence chaining while brute-forcing #AdventOfCode day 2, but I have no regrets

github.com/tcbrindle/ad...

$auto is_invalid_id_p1 = [](u64 id) -> bool { auto const str = to_string(id); auto mid = str.size() / 2; return flux::equal(flux::ref(str).take(mid), flux::ref(str).drop(mid)); }; auto is_invalid_id_p2 = [](u64 id) -> bool { auto const str = to_string(id); return flux::iota(1uz, 1 + str.size() / 2) .filter([&](auto sz) { return str.size() % sz == 0; }) .map([&](auto sz) { return flux::ref(str).chunk(sz); }) .any([](flux::multipass_sequence auto chunks) { auto first = chunks.front().value(); return std::move(chunks).drop(1).all( [&](auto chunk) { return flux::equal(chunk, first); }); }); }; template <auto TestFn> auto test_ranges = [](std::vector<id_range> const& input) -> u64 { return flux::ref(input) .map([](id_range rng) { return flux::iota(rng.from, rng.to + 1); }) .flatten() .filter(TestFn) .sum(); }; auto part1 = test_ranges<is_invalid_id_p1>; auto part2 = test_ranges<is_invalid_id_p2>;$

December 2, 2025 at 12:59 PM

meetingcpp.bsky.social

@meetingcpp.bsky.social

C++20s `std::source_location` in action
andreasfertig.com/blog/2025/12...
#cpp
#cplusplus

C++20s `std::source_location` in action

In today's post, I want to address a question I'm getting occasionally when teaching a C++20 class. From the plenty of new features tha...

andreasfertig.com

December 2, 2025 at 11:36 AM

Reposted

Matt Godbolt

@matt.godbolt.org

Day 2: Adding two integers on x86? Not with `add`! The compiler uses a completely different instruction—one designed for memory addressing. Why? xania.org/202512/02-ad... youtu.be/BOvg0sGJnes #AoCO2025

Addressing the adding situation — Matt Godbolt’s blog

We learn why adding on x86 isn't as obvious as you might think

xania.org

December 2, 2025 at 11:28 AM