[mischief6]

not a rust programmer. can someone explain why this is in the final binary and not in a shared library?

[simonask]

The Rust compiler statically links everything into a single binary. This can be changed, but is generally discouraged as there are no ABI stability guarantees at this point.

[zozbot234]

You can use the C ABI if you want something stable, and there are custom crates that will help with translating from the Rust to the C ABI. (This also helps because the resulting shared objects can potentially be FFI'd with from any language, not just Rust. They might as well be plain C libraries as far as anyone is concerned, only with the usual Rust safety requirements.)