explaine.rs is an interactive playground to explore the syntax of the Rust Programming Language.
You can write any Rust code in the editor and the analyzer will allow you to click/tap on different keywords, punctuation elements and other bits of code and help you understand what they mean.
This is a work in progress! Please submit your feedback in the repository.
Should we show a hint for this code?
Is there some syntax we should explain?
You can also find a syntax glossary in the Rust Book.
It looks like your code just needs to be wrapped in a declaration.