Openarray and iterable typeclasses do not match properly.

[beef331]

Iterable cannot be combined with other types for a typeclass.

Example

type IntIter = openArray[int] or iterable[int]

template doThing(a: IntIter) =
  for x in a:
    echo x

iterator tIter(a: int): int =
  for x in 0..a:
    yield x

doThing([10, 20, 30, 40])
doThing(tIter(100))

Current Output

Error: type mismatch: got <array[0..3, int]>
but expected one of:
template doThing(a: IntIter)
  first type mismatch at position: 1
  required type for a: IntIter
  but expression '[10, 20, 30, 40]' is of type: array[0..3, int]

expression: doThing([10, 20, 30, 40])

Expected Output

Compiles fine.

Possible Solution

If the only matches are ones that use iterable[T], check if items/pairs match the T.

[beef331]

After further investigation, seems it's the same for both openArray and iterable using either in a type class results in failure. So relates to: https://github.com/nim-lang/Nim/issues/15722

proc doThing(a: openArray[int] or int) = echo a
doThing(@[10, 20, 30]) # This fails
doThing([10, 20, 30]) # This aswell
#doThing(1) This works

[timotheecour]

see https://github.com/nim-lang/RFCs/issues/397