> This is a fun one. @Dragon-Hatcher created a very unusual Rust program: a chess engine that computes things at compile time only using Rust’s Turing-complete

> This is a fun one. @Dragon-Hatcher created a very unusual Rust program: a chess engine that computes things at compile time only using Rust’s Turing-complete trait system. (They also have a TypeScript version of the same program.) This causes vast numbers of trait obligations to be generated for the compiler’s trait solver. In this PR I made some small changes to a de-duplication step that runs on collections of these obligations, which reduced both the compile time and peak memory usage of this crate by almost 7x! It also gave icount wins of up to 4% across a number of secondary benchmarks. Type System Acrobatics have their use.