[pornel]

Giving good feedback about Rust<>C bindings requires knowing Rust well. It needs deep technical understanding of Rust's safety requirements, as well as a sense of Rust's idioms and design patterns.

C maintainers who don't care about Rust may have opinions about the Rust API, but that's not the same thing :)

There are definitely things that can be done in C to make Rust's side easier, and it'd be much easier to communicate if the C API maintainer knew Rust, but it's not necessary. Rust exists in a world of C APIs, none of which were designed for Rust.

The Rust folks can translate their requirements to C terms. The C API needs to have documented memory management and thread safety requirements, but that can be in any language.