interface Any {}

fn do(v Any) string {
    match v {
        int {
            println('> integer answer: ${2 * v}')
            return '${2 * v}'
        }
        string {
            println('> string answer: ${v}, len: ${v.len}')
            return '${v}'
        }
        else {
            return ''
        }
    }
}

fn test_printing_smartcast_interface_variable() {
    s1 := do(123)
    assert s1 == '246'

    s2 := do('abc')
    assert s2 == 'abc'
}