use std::io::{self, Write};
use std::f64;

fn main() {
    println!("Let's print some lines:");
    println!();
    println!("Hello, world!");
	println!("{}, {}!", "Hello", "world");
    println!("Arguments can be referred to by their position: {0}, {1}! and {1}, {0}! are built from the same arguments", "Hello", "world");

	println!("Furthermore the arguments can be named: \"{greeting}, {object}!\"", greeting = "Hello", object = "World");

	println!("Number formatting: Pi is {0:.3} or {0:.0} for short", f64::consts::PI);

    println!("... and there is more: {0:>0width$}={0:>width$}={0:#x}", 1535, width = 5);
    print!("Printing without newlines ... ");
    println!("is great");
    
    let _ = write!(&mut io::stdout(), "Underneath, it's all writing to a stream...");
    println!();

    println!("Write something!");
    let mut input = String::new();
    if let Ok(n) =  io::stdin().read_line(&mut input) {
        println!("You wrote: {} ({} bytes) ", input, n);
    }
    else {
        eprintln!("There was an error :(");
    }
}