alt Hacker News> We know the result isn’t idiomatic Rust, and there’s a lot that can be simplified once we’re comfortable retiring the C++ pipeline. That cleanup will come in time.
I wonder what kind of tech debt this brings and if the trade off will be worth whatever problems they were having with C++.
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I don't think they were having problems with C++, they moved to Rust for memory safety. Mind that they migrated LibJS, their JavaScript library.
Andreas Kling mentioned many times they would prefer a safer language, specifically for their js runtime garbage collector. But since the team were already comfortable with cpp that was the choice, but they were open and active seeking alternatives.
The problem was strictly how cpp is perceived as an unsafe language, and this problem rust does solve! Not being sarcastic, this truly looks like a mature take. Like, we don't know if moving to rust would improve quality or prevent vulnerabilities, here's our best effort to find out and ignore if the claim has merits for now. If the claim maintains, well, you're better prepared, if it doesn't, but the code holds similar qualities...what is the downside?
the tech debt risk in this case is mostly in the cleanup phase, not the port itself. non-idiomatic Rust that came from C++ tends to have a lot of raw pointer patterns and manual lifetime management that works fine but hides implicit ownership assumptions. when you go to make it idiomatic, the borrow checker forces those assumptions to be explicit, and sometimes you discover the original structure doesn't compose well with Rust's aliasing rules. servo went through this. the upside is you catch real latent bugs in the process.