code and bitters

What does the trait bound 'static mean in Rust?

After a few weeks of programming in Rust we should have a pretty good idea of what a 'static reference is, but a 'static trait bound can seem a bit more mysterious.

The first time I had to add a 'static trait bound to my code. I didn't feel like I understood what was happening, because there were no references involved. In fact, the only data involved were function arguments being passed by ownership, which is usually a pretty reliable way of avoiding borrow checker problems.

In many cases, the rust compiler will suggest a 'static trait bound to address a problem. The compiler is probably right, but let's explore what it really means so we can be confident that we understand the solution.

Here's a quick question to test your Rust knowledge: which of these lines of code do the same thing?

drop(a);
let _ = b;
c;

Updated 10/2021 to use nom 7.0!

This is a demonstration of building a parser in Rust using the nom crate. I recently built a parser for the cddl-cat crate using nom, and I found it a surprisingly pleasant experience, much better than my past experiences with other parser-generators in other languages.

Since I like Rust a lot, and I need an excuse to do more writing about Rust, I thought I'd do another demonstration project. I decided to choose a simple syntax, to keep this a short project. So I'm going to build a parser for JSON.

I've been experimenting with Rust lately, and have just started following Jon Gjengset's videos. In his latest livestream, Jon started a port of the Java ConcurrentHashMap to Rust. I highly recommend them; it's fun to see how someone with a lot of Rust experience approaches problems.

One of the things that grabbed my attention was his use of crossbeam::epoch. It's a library that helps you write certain kinds of lock-free concurrent data structures, using an "epoch counter" that allows you to disconnect objects from your main data structure and they will be freed later-- without using any per-object atomic reference counters or other major GC overhead.

How… interesting.

An open source program (ogg123) has been crashing repeatedly on my new laptop. The source code hasn’t changed in years. The stacktrace always points to __lll_unlock_elision() in glibc, which seems kind of scary. Searches on the web all seem to point back to problems with Haswell CPUs that have broken TSX instructions, and are running out-of-date microcode.