Function smallest_decimal

cpp/src/arrow/type.cc:3349–3354

}

std::shared_ptr<DataType> smallest_decimal(int32_t precision, int32_t scale) {
  return precision <= Decimal32Type::kMaxPrecision    ? decimal32(precision, scale)
         : precision <= Decimal64Type::kMaxPrecision  ? decimal64(precision, scale)
         : precision <= Decimal128Type::kMaxPrecision ? decimal128(precision, scale)
                                                      : decimal256(precision, scale);
}

std::shared_ptr<DataType> decimal32(int32_t precision, int32_t scale) {
  return std::make_shared<Decimal32Type>(precision, scale);