use std::collections::HashMap;

fn main() {
    // I want to check of the the last element of v is an opening bracket that
    // can be closed by maybe_closing_char
    let v = ['a', 'b', 'c', '('];
    let maybe_closing_char = ')';
    // closing_char should tell me which charater would be fitting to close the
    // brackets. We need an Option for that, because we can't be sure there is
    // any such character.
    // This works
    let closing_char = match v.last() {
        Some('[') => Some(']'),
        Some('(') => Some(')'),
        Some('{') => Some('}'),
        _   => None,
    };
    // I would like to use a HashMap instead (so I can reuse it later).
    // This seems to be more elegant, but doesn't work. The &* were inserted in
    // an attempt to satisfy the compilier.
    let brackets_matchers: HashMap<char, char> =
        [('(', ')'),
         ('[', ']'),
         ('{', '}')]
        .iter().cloned().collect(); // easiest way to create a HashMap I know of
    // comment out this line to see it working
    let closing_char = v.last().and_then(|l| brackets_matchers.get(&*l));

    if Some(maybe_closing_char) == closing_char {
        println!("Can close")
    } else {
        println!("Can't close")
    }

    println!("closing_char: {:?}", closing_char);
    println!("Hello, world!");
}