#!/usr/bin/ruby
subset foo < Str, Num
struct Bar {
    a < foo,
    b < foo,
}
var t = Bar(:hi, 100)
assert_eq(t.a, :hi)
assert_eq(t.b, 100)
do {
    var ok = false
    try {
        Bar([], {})
    }
    catch {
        ok = true
    }
    assert(ok)
}