[$] Existential types in Rust

For several years, contributors to the Rust project have
been working to improve support for asynchronous
code. The benefits of these efforts are not confined to asynchronous code,
however. Members of the Rust community have been working toward adding explicit

existential types to Rust since 2017. Existential types are not a common feature
of programming languages (something

the RFC acknowledges), so the motivation for their inclusion might be somewhat
obscure.