tinyvec VS session-types

funny indeed. i changed all my projects to use tinyvec

I've seen the cost of zeroing memory be measurable, or maybe significant enough to care about, but I've never seen 90% of cycles spent on it, the only case I know of that gets close is creating an empty TinyVec versus an empty SmallVec with an inline buffer of 256 bytes. In my opinion that's an unreasonably large inline buffer. At inline buffers of 128 bytes and below, the overhead is less than 50%, and that's on a microbenchmark of the Default impl; the effect is rapidly diluted in a real program.

My point is that "implementation that doesn't use unsafe" is not necessarily always slower than "implementation that does use unsafe". Often people assume that this is the case, and it isn't. tinyvec currently beats smallvec in more than a few benchmarks. Not all, but some. And this sometimes visible to users. The point is that if you want speed, you don't necessarily need to give up any safety at all. Most differences in performance are due to the amount of effort or expertise that has been spent on the codebase, not the amount of unsafe in it.

https://github.com/Lokathor/tinyvec will definitely benefit, although not as much as something currently relying on typenum.

But there's no law of nature that says that Rust type-level syntax must suck forever. Maybe Rust 2036 will make writing this stuff a breeze, who knows. But for now, there are some projects that attempt to fill this gap, like Tyrade, which is a Rust DSL (like, a proc macro) that compiles down to bare Rust. It has seen some usage: there's a session types library built on top of Tyrade that is just awesome:

Since this often matters when implementing protocols, there is research about session types and verification. Here is a Rust library for session types: https://github.com/Munksgaard/session-types

I believe both have some overlap.