One-liners#
Single-expression idioms the operator pastes into a Rust file.
Read a whole text file.
let text = std::fs::read_to_string("notes.txt")?;
Write a whole file.
std::fs::write("out.bin", &payload)?;
Parse an integer with ?.
let n: i64 = s.parse()?;
Collect an iterator into a Vec.
let v: Vec<_> = xs.iter().map(|x| x * 2).collect();
Filter, map, collect.
let v: Vec<_> = xs.iter().filter(|&&x| x % 2 == 0).map(|x| x * x).collect();
Sum of squares.
let total: i64 = xs.iter().map(|x| x * x).sum();
Top-N by key.
let top: Vec<_> = xs.iter().take(10).collect();
Default value with unwrap_or.
let port = cfg.port.unwrap_or(8080);
Pretty-print JSON with serde_json.
let s = serde_json::to_string_pretty(&obj)?;
Open a TCP connection with a timeout.
let stream = std::net::TcpStream::connect_timeout(&addr, std::time::Duration::from_secs(3))?;