class FFI::Bitmask

def to_native(query, ctx)
  return 0 if query.nil?
  flat_query = [query].flatten
  res = flat_query.inject(0) do |val, o|
    case o
    when Symbol
      v = @kv_map[o]
      raise ArgumentError, "invalid bitmask value, #{o.inspect}" unless v
      val | v
    when Integer
      val | o
    when ->(obj) { obj.respond_to?(:to_int) }
      val | o.to_int
    else
      raise ArgumentError, "invalid bitmask value, #{o.inspect}"
    end
  end
  # Take two's complement of positive values bigger than the max value
  # for the type when native type is signed.
  if @signed && res >= (1 << (@native_type.size * 8 - 1))
    res = -(-res & ((1 << (@native_type.size * 8)) - 1))
  end
  res
end