fn find_startswith_string(a []string, search string) ?string {
    for s in a {
        if s.starts_with(search) {
            return s
        }
    }
    return none
}

fn find_any_startswith_string(a []string, b []string, search string) ?string {
    // cannot convert 'struct _option_string' to 'struct string'
    // V wants the or {} block to return a string, but find_startswith_string returns ?string
    return find_startswith_string(a, search) or { find_startswith_string(b, search)? }
}

fn find_any_startswith_string_unwrapped(a []string, b []string, search string) ?string {
    return find_startswith_string(a, search) or { find_startswith_string(b, search)? }
}

fn test_main() {
    var1 := find_any_startswith_string(['foobar', 'barfoo'], ['deadbeef', 'beefdead'], 'dead')
    assert var1 or { panic('unreachable') } == 'deadbeef'
    dump(var1)

    var2 := find_any_startswith_string_unwrapped(['foobar', 'barfoo'], ['deadbeef', 'beefdead'],
        'dead')
    dump(var2)
    assert var2 != none

    var3 := find_any_startswith_string_unwrapped(['foobar', 'barfoo'], ['deadbeef', 'beefdead'],
        'error')
    dump(var3)
    assert var3 == none
}