That's false. From[1], it looks like two submissions use `unsafe`. And one of those is for ffi to gmp.
[1] - http://benchmarksgame.alioth.debian.org/u64q/rust.html
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
2 pi-digits (ffi to gmp)
https://www.reddit.com/r/programming/comments/62cx5d/addendu...
There are many ways to be selective with evidence.
As-a-matter-of-fact all the contributed Rust programs I listed use unsafe.
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
2 pi-digits (ffi to gmp)
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...