Right, I guess the question is what will that proportion be when Rust is used for things like operating systems and web browsers. 30% would be untenable but a f

Right, I guess the question is what will that proportion be when Rust is used for things like operating systems and web browsers. 30% would be untenable but a few hundred/thousand lines of unsafe code is fairly easy to put under a microscope. For some current day research into this, there is the paper "How Do Programmers Use Unsafe Rust?"[1] which I'll drop a quote from here: > The majority of crates (76.4%) contain no unsafe features at all. Even in most crates that do contain unsafe blocks or functions, only a small fraction of the code is unsafe: for 92.3% of all crates, the unsafe statement ratio is at most 10%, i.e., up to 10% of the codebase consists of unsafe blocks and unsafe functions That paper is definitely worth reading and goes into why programmers use unsafe. e.g 5% of the crates at that time were using it to perform FFI. In writing "RUDRA: Finding Memory Safety Bugs in Rust at the Ecosystem Scale" [2], I recreated this data and year-by-year the % of crates using unsafe is going down. And for what it's worth, crates are probably a bad data-set for this. crates tend to be libraries which are exactly where we would expect to find unsafe code encapsulated to be used safely. There's also plenty of experimental and hobby crates. A large dataset of actual binaries would be way more interesting to look at. [1] https://dl.acm.org/doi/10.1145/3428204 https://dl.acm.org/doi/10.1145/3428204 [2] https://taesoo.kim/pubs/2021/bae:rudra.pdf https://taesoo.kim/pubs/2021/bae:rudra.pdf