BitVector = object
  bits: seq[uint64]
  csum: seq[int]

CPLIB_COLLECTIONS_BITVECTOR = 1

proc `[]`(self: var BitVector; idx: int): bool {....raises: [], tags: [].}

proc access(self: var BitVector; idx: int): bool {....raises: [], tags: [].}

proc build(self: var BitVector) {....raises: [], tags: [].}

proc newBitVector(length: int): BitVector {....raises: [], tags: [].}

proc rank(self: var BitVector; idx: int): int {....raises: [], tags: [].}

proc set(self: var BitVector; idx: int) {....raises: [], tags: [].}