Method SparseUnion

cpp/src/arrow/testing/random.cc:999–1011

}

std::shared_ptr<Array> RandomArrayGenerator::SparseUnion(const ArrayVector& fields,
                                                         int64_t size, int64_t alignment,
                                                         MemoryPool* memory_pool) {
  DCHECK_GT(fields.size(), 0);
  // Trivial type codes map
  std::vector<UnionArray::type_code_t> type_codes(fields.size());
  std::iota(type_codes.begin(), type_codes.end(), 0);

  // Generate array of type ids
  auto type_ids = Int8(size, 0, static_cast<int8_t>(fields.size() - 1),
                       /*null_probability=*/0, alignment, memory_pool);
  return *SparseUnionArray::Make(*type_ids, fields, type_codes);
}

std::shared_ptr<Array> RandomArrayGenerator::DenseUnion(const ArrayVector& fields,
                                                        int64_t size, int64_t alignment,