// Define a simple macro named `say_hello`
// that takes a name as an argument.
macro_rules! say_hello {
    ($name:expr) => {
        println!("Hello, {}!", $name);
    };
}

// Define a macro named `create_map`
// that takes key-value pairs and creates a HashMap.
macro_rules! create_map {
    ($($key:expr => $value:expr),*) => {{
        use std::collections::HashMap;
        let mut map = HashMap::new();
        $(
            map.insert($key, $value);
        )*
        map
    }};
}

fn main() {
    // Use the `say_hello` macro.
    say_hello!("Alice");
    say_hello!("Bob");

    // Use the `create_map` macro.
    let map = create_map! {
        "one" => 1,
        "two" => 2,
        "three" => 3
    };

    println!("The created map is: {:?}", map);
}