-- in.cue --
#A: {
	a: string
}

#B: {
	b: string
}

#X: #A | #B

l: [...#X]

l: [
	{b: "bar"},
]
-- out/eval/stats --
Leaks:  0
Freed:  17
Reused: 12
Allocs: 5
Retain: 0

Unifications: 13
Conjuncts:    25
Disjuncts:    17
-- out/eval --
(struct){
  #A: (#struct){
    a: (string){ string }
  }
  #B: (#struct){
    b: (string){ string }
  }
  #X: (#struct){ |((#struct){
      a: (string){ string }
    }, (#struct){
      b: (string){ string }
    }) }
  l: (#list){
    0: (#struct){
      b: (string){ "bar" }
    }
  }
}
-- out/compile --
--- in.cue
{
  #A: {
    a: string
  }
  #B: {
    b: string
  }
  #X: (〈0;#A〉|〈0;#B〉)
  l: [
    ...〈1;#X〉,
  ]
  l: [
    {
      b: "bar"
    },
  ]
}