I’ve become very interested in Rust over the past few months, and I’ve paid particular attention to the language’s potential as a successor to C. The recent inclusion of Rust in the Linux kernel certainly adds credibility to the notion that many codebases currently written in C may one day be re-written in Rust. This leads me to wonder about the advantages which C may still enjoy over its younger rival. One area in which C wipes the floor with Rust is arbitrarily large integers. Rust’s num_bigint crate is slower than Python; C’s GMP is still king. But this – I presume – is a gap which will eventually be filled. Are there any more permanent gaps?