Rust is a programming language that very much emphasises safety.
One of the cornerstones is that it warns on constructs that might lose information or make object lifetime unclear.
An example is discarding function results: historically you will get a warning like warning: unused `std::result::Result` that must be used that you can resolve by applying a let statement assigning to the _ underscore pattern which will be discarded at the end of the statement like this:
The Wiert Corner - irregular stream of stuff 