trpl-zh-cn/listings/ch05-using-structs-to-structure-related-data/output-only-02-pretty-debug/output.txt

$ cargo run
   Compiling rectangles v0.1.0 (file:///projects/rectangles)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.48s
     Running `target/debug/rectangles`
rect1 is Rectangle {
    width: 30,
    height: 50,
}