proc createSequence: seq[int] =
  result = @[10, 20]

proc mainProc =
  let a = createSequence()
  let b = a[0].unsafeAddr # OK

  for x in a:
    let c = x.unsafeAddr # Error

  for i in 0..<a.len:
    let c = a[i].unsafeAddr # OK

  for i in 0..<a.len:
    let x = a[i]
    let c = x.unsafeAddr # OK

if isMainModule:
  mainProc()