C++11 to C++23 in the C++ Memory Model - Alex Dathskovsky - C++Now 2024

[@sarevoker]

Cheers from Brazil, thanks for this presentation, very insightful.

[@shivratanyadav8307]

Hi, can you clear up my doubts related to the C++ programming language? I know that C++ is a language, but what are C++18, C++20, C++23, and C++24? As a beginner, after learning basic C++, will I need to learn these as well to become an expert in C++? Please help clear up my confusion. Thank you for your time and suggestions.

[@srh80]

46:44 just pointing out, Its possible for threads to observe other intermediate states (other than 1,2). Seq cst does not guarantee the order of independent events, it only guarantees that all observers will agree on a single order.

[@momoanddudu]

Alex is a C++ expert, and a great lecturer. Great video!

[@BoostCon]

So pleased to hear you enjoyed this presentation by Alex Dathskovsky.

[@peregrin71]

Are scopes re-ordering barriers too? I get that reordering is possible within one scope, but is it allowed for C++ compilers to re-order across scopes? In other words can I add local scopes to functions to enforce a certain ordering?

[@WilhelmDrake]

@14:00 UB can sneak past even the best of us. I know there are sanitizers to detect some UB but I really wish there was a way to get compilers to treat UB as an error.

[@aniketbisht2823]

UB means that the compilers get to assume certain conditions (pre-conditions) about particular statements and optimize based on that. If you force the compiler to define a behaviour for the violation of those preconditions then the compiler doesn't get that privilege (to optimize).

[@JohnDlugosz]

UB has a run-time component, so it's not just treating the construct as an error, but inserting tests. Things that _are_ strictly compile-time probably do have warnings/errors that can be enabled.

[@filosofisto]

That was simply a spectacular speech

[@keyboard_toucher]

8:03 You don't need to consider "a very bad coder" to have code like "v + 1 + 3" occur. The 1 and 3 could be the values of symbols as in "v + x + y" where x and y happen to be known to be 1 and 3 respectively.

[@SamWhitlock]

16:45 I never realized how compilers used `lea` on a random address to use the address calculation instead of the integer calculation. That's clever!

[@sunnyyasser5625]

thats a lot of info condesnsed into 1 talk

[@JohnDlugosz]

15 minutes in, the video glitches and the audio does not, so it's out of sync by a couple seconds. That's why you always proof the final encoded file, before uploading. Fortunately, it glitches back half a minute later, so it's not doing that for the entire video. I wonder what else is going to happen over the course of 90 minutes.