RustTutorials/debugging.rs

// Derive the `fmt::Debug` implementation for `Structure`. `Structure`
// is a structure which contains a single `i32`.
#[derive(Debug)]
struct Structure(i32);

// Put a `Structure` inside of the structure `Deep`. Make it printable
// also.
#[derive(Debug)]
struct Deep(Structure);

#[derive(Debug)]
struct Person<'a>{
	name: &'a str,
	age: u8
}

fn main(){
	//Printing with `{:?}` is similar to with `{}`.
	println!("{:?} months in a year.", 12);
	println!("{1:?} {0:?} is the {actor:?} name.",
			 "Slater",
			 "Christian",
			 actor="actor's");

	//`Structure` is printable!
	println!("Now {:?} will print!", Structure(3));
	
	//The problem with `derive` is there is no control over how
	//the results look. What if I want this to just show a `7`?
	println!("Now {:?} will print!", Deep(Structure(7)));
	
	let name = "Peter";
	let age = 27;
	let peter = Person { name, age };

	//Pretty print
	println!("{:#?}", peter);
}