example.cc

#include "arrow/array/array_base.h"
#include "arrow/record_batch.h"
#include "arrow/result.h"
#include <iostream>
#include <memory>
#include <stddef.h>

#include <arrow/api.h>
#include <arrow/compute/api.h>

arrow::Result<std::shared_ptr<arrow::RecordBatch>> MakeABatch() {
  // Build an Array to add to the batch
  std::vector<int32_t> vec{1, 2, 3, 4, 5};
  size_t n = 5;
  arrow::Int32Builder i32;
  size_t size = vec.size();
  i32.AppendValues(std::vector<int32_t>(size, n));
  auto a_n = i32.Finish().ValueOrDie();

  // Build an initial RecordBatch
  auto field = arrow::field("f1", arrow::int32());
  auto schema = ::arrow::schema({field});
  auto rbatch = arrow::RecordBatch::Make(
      schema, n, std::vector<std::shared_ptr<arrow::Array>>{a_n});

  // Return the result of adding the column to the batch
  return rbatch->AddColumn(0, arrow::field("n", arrow::int32(), false), a_n);
}

arrow::Status RunMain() {
  ARROW_ASSIGN_OR_RAISE(auto new_batch, MakeABatch());

  std::cout << new_batch->schema()->ToString() << std::endl;
  std::cout << new_batch->num_rows() << "x" << new_batch->num_columns()
            << std::endl;

  return arrow::Status::OK();
}

int main() {
  arrow::Status st = RunMain();
  if (!st.ok()) {
    std::cerr << st << std::endl;
    return 1;
  }
  return 0;
}

output.txt

n: int32 not null
f1: int32
5x2