libcxx VS julia

If you are comparing hoops that library authors need to jump through in both languages, you can easily make the real-world comparison in the other direction, by comparing Rust's Option with C++'s std::optional (an exercise left for the reader): Rust std: https://github.com/rust-lang/rust/blob/master/library/core/src/option.rs libcxx: https://github.com/llvm-mirror/libcxx/blob/master/include/optional

My favorite prime number generator is the undocumented __next_prime():

https://github.com/llvm-mirror/libcxx/blob/78d6a7767ed57b501...

There is no good reason to use this one except in a code golf environment that includes all headers by default, which is where I learned about it.

I once read a Strousroup quote amounting to "If you understand std::vector, then you understand C++". I thought surely he couldn't have meant the interface but the implentation, googled that llvm's implementation is considered nice and clean, had a look, and noped straight out of there.

C++'s STL linked list for comparison (libcxx).

https://github.com/llvm-mirror/libcxx/blob/master/include/li...

> For example, accessing a std::span or a std::vector outside of its bounds would abort the program, and so would accessing an empty std::optional.

I don't really understand the difference with libc++, libstdc++ and msvc stl's respective debug modes, they already do exactly these checks :

- https://github.com/llvm-mirror/libcxx/blob/78d6a7767ed57b501...

- https://github.com/gcc-mirror/gcc/blob/966010b2eb4a4c52f139b...

I mean it's not hard to read the source for your platform. On Linux/x86_64/libc++ it's roughly:

- https://github.com/llvm-mirror/libcxx/blob/master/include/__...

- https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=nptl/...

I don't particularly care to comb through it to see if anything has changed, but historically it was a a little spin-CAS to make the non-contended path fast and then dropping into a https://en.wikipedia.org/wiki/Futex, which is about as good as it gets for staying mostly in userspace but still letting it be scheduler aware so you're not burning up a core busy-polling, which is what often happens when people try to roll their own shit.

Google wants a bit more latitude on the heuristics and degrees of freedom around read/write ownership, so they did it like this: https://github.com/abseil/abseil-cpp/blob/master/absl/synchr... which is quite a bit better commented/legible.

If anyone reading this can do better than the `abseil-cpp` folks, not only would Google take their PR, they'd probably offer them a job.

34. Julia - $74,963

I don't believe there is any official documentation on this, but https://github.com/JuliaLang/julia/pull/49430 for example added prefetching to the marking phase of a GC which saw speedups on x86, but not on M1.

3. dispatch on all the arguments

the first solution is clean, but people really like dispatch.

the second makes calling functions in the function call syntax weird, because the first argument is privileged semantically but not syntactically.

the third makes calling functions in the method call syntax weird because the first argument is privileged syntactically but not semantically.

the closest things to this i can think of off the top of my head in remotely popular programming languages are: nim, lisp dialects, and julia.

nim navigates the dispatch conundrum by providing different ways to define free functions for different dispatch-ness. the tutorial gives a good overview: https://nim-lang.org/docs/tut2.html

lisps of course lack UFCS.

see here for a discussion on the lack of UFCS in julia: https://github.com/JuliaLang/julia/issues/31779

so to sum up the answer to the original question: because it's only obvious how to make it nice and tidy like you're wanting if you sacrifice function dispatch, which is ubiquitous for good reason!

https://github.com/JuliaLang/julia/blob/release-1.10/NEWS.md

Visit official site: https://julialang.org/

No. It runs natively on ARM.

julia> versioninfo() Julia Version 1.9.3 Commit bed2cd540a1 (2023-08-24 14:43 UTC) Build Info: Official https://julialang.org/ release

https://github.com/JuliaLang/julia/issues/51086#issuecomment...

So while this "fixes" the issue, it'll introduce a confusing time delay between you freeing the memory and you observing that in `htop`.

But according to https://jemalloc.net/jemalloc.3.html you can set `opt.muzzy_decay_ms = 0` to remove the delay.

Still, the musl author has some reservations against making `jemalloc` the default:

https://www.openwall.com/lists/musl/2018/04/23/2

> It's got serious bloat problems, problems with undermining ASLR, and is optimized pretty much only for being as fast as possible without caring how much memory you use.

With the above-mentioned tunables, this should be mitigated to some extent, but the general "theme" (focusing on e.g. performance vs memory usage) will likely still mean "it's a tradeoff" or "it's no tradeoff, but only if you set tunables to what you need".

I have asked about Julia's reproducibility story on the Guix mailing list in the past, and at the time Simon Tournier didn't think it was promising. I seem to recall Julia itself didnt have a reproducible build. All I know now is that github issue is still not closed.

https://github.com/JuliaLang/julia/issues/34753

I don't really know what kind of rebuttal you're looking for, but I will link my HN comments from when this was first posted for some thoughts: https://news.ycombinator.com/item?id=31396861#31398796. As I said, in the linked post, I'm quite skeptical of the business of trying to assess relative buginess of programming in different systems, because that has strong dependencies on what you consider core vs packages and what exactly you're trying to do.

However, bugs in general suck and we've been thinking a fair bit about what additional tooling the language could provide to help people avoid the classes of bugs that Yuri encountered in the post.

The biggest class of problems in the blog post, is that it's pretty clear that `@inbounds` (and I will extend this to `@assume_effects`, even though that wasn't around when Yuri wrote his post) is problematic, because it's too hard to write. My proposal for what to do instead is at https://github.com/JuliaLang/julia/pull/50641.

Another common theme is that while Julia is great at composition, it's not clear what's expected to work and what isn't, because the interfaces are informal and not checked. This is a hard design problem, because it's quite close to the reasons why Julia works well. My current thoughts on that are here: https://github.com/Keno/InterfaceSpecs.jl but there's other proposals also.

Doesn't musl have the same issue? https://github.com/JuliaLang/julia/issues/34726#issuecomment...

I also wonder about OSX's libc. Newer versions seem to have some sort of locking https://github.com/apple-open-source-mirror/Libc/blob/master...

but older versions (from 10.9) don't have any lockign: https://github.com/apple-oss-distributions/Libc/blob/Libc-99...