portable-simd VS config-rs

Jubilee and Caleb Zulawski for their tireless work on the portable SIMD project. It will land, some day, and when it does it's going to be an amazing boon for the project.

The portable SIMD project implements an as_simd() function for slices. The basics are that you get 3 slices and the middle one is a SIMD slice. It allows for fast aligned loads of the data, which could matter if your algorithm is becoming memory bound; it is also a convenient and safe abstraction. In my case, I actually have 2 vectors (say, x and y). I can take them apart using as_simd() like so:

Rust has generics and monomorphization. You can write the algorithm once and compile for multiple targets. rust-lang/portable-simd

This Rust issue [0] was the best short summary of what an SIMD Shuffle is I could find:

„A "shuffle", in SIMD terms, takes a SIMD vector (or possibly two vectors) and a pattern of source lane indexes (usually as an immediate), and then produces a new SIMD vector where the output is the source lane values in the pattern given.“

[0] https://github.com/rust-lang/portable-simd/issues/11

Yet by default it generates code which is only compatible with Pentium4 or newer. In fact lots of serious issues relate to older CPUs and rustc developers plan is to declare them closed when they would be able to drop i686 support (all AMD CPUs which support SSE2 support x86-64, too while Intel situation is mess).

The standard API crate for portable simd is at https://github.com/rust-lang/portable-simd, but using this requires nightly, which I don't want to do. I'd like to use a crate for simd that works on both x86_64 and wasm in stable rust. wide looks fine for this purpose. Are there any potentially better choices?

See: https://github.com/rust-lang/portable-simd

As for portable SIMD, there's relatively recent activity (last commit 20 days ago) on this repository: https://github.com/rust-lang/portable-simd

I like config.rs, but I am struggling to overwrite config profiles with environment variables. The desired config is mixed, like .toml

Consider config crate. It could be like:

I've been using Config most of the time. I also use once_cell to make it a static variable.

I've enjoyed using this one: https://crates.io/crates/config

Anyone know of a library like https://github.com/netflix/go-env but for rust? I found https://github.com/mehcode/config-rs but it's just not as simple...

I was just in that space today. The config crate has an example you might find useful: https://github.com/mehcode/config-rs/tree/master/examples/hierarchical-env

How it differs from config?

Checking an environment variable is very easy with std::env::var or similar. If you have other bits of configuration that also change—which is typical; things like DB connection strings—you may consider a more full-featured solution like https://docs.rs/config/0.10.1/config/ (pay particular attention to this example, which seems to be very close to what you want: https://github.com/mehcode/config-rs/blob/master/examples/hierarchical-env/src/settings.rs ).

It's unfortunate, it looks like there was an attempt to get someone else to maintain it here, but no one ended up really stepping up to the plate.