> An exciting feature just landed in the main branch of the Clang compiler. Using the [[clang::musttail]] or __attribute__((musttail)) statement attributes, you can now get guaranteed tail calls in C, C++, and Objective-C.
> What does Rust have to do with this? Nothing.
Rust has a planned keyword for this exact feature, namely 'become'. So the author would be able to use it in Rust just as well, as soon as support for it lands in an upstream LLVM release.
Regardless, writing raw C as the article suggests in order to parse a quasi-standard high-level format is cowboy coding. It's a nice hack to be sure, but it's not the kind of code that should be anywhere close to a real production workload. Instead, this feature should be implemented as part of some safe parser generator. Not necessarily written in Rust but something that's at least as safe.