Rust Quick Start Guide

Type inference

As we noticed earlier, we can specify the type of a variable, but we often don't have to. That's because Rust has a feature called type inference, which often lets it figure out what type a variable is by looking at what we do with it. For example, if we were using the Tokio networking library, we might use code such as this:

let addr = "127.0.0.1:12345".parse()?;let tcp = TcpListener::bind(&addr)?;

We didn't specify what type the addr variable should have. Even more interesting, we didn't tell the text address what kind of information we needed it to parse into.

Parsing means transforming a representation into usable data, approximately. Lots of things can be represented as a string of text, if you know how to parse that text ...