/// Creates a HashMap containing the arguments
///
/// - Create a HashMap containing a given list of elements:
/// ```
/// let m = hashmap!["five" => 5, "six" => 6];
///
/// assert_eq!(*m.get(&"five").unwrap(), 5);
/// assert_eq!(*m.get(&"six").unwrap(), 6);
/// ```
/// Verify that an expression matches a pattern
///
/// ```
/// let a = Some(42);
/// let b = Some(42);
///
/// assert!(matches!(a, b);
///