message: Adding Arrow guardrails
diff: #include <stdint.h>
  +
  #ifdef __cplusplus
  extern "C" {
  #endif
  @@ -18,6 +19,7 @@ extern "C" {
  #define ARROW_FLAG_NULLABLE 2
  #define ARROW_FLAG_MAP_KEYS_SORTED 4
  +#ifndef ARROW_C_DATA_H
  struct ArrowSchema {
  // Array type description
  const char *format;
  @@ -75,6 +77,7 @@ struct ArrowArrayStream {
  // Opaque producer-specific data
  void *private_data;
  };
  +#endif
  #ifdef __cplusplus
  }
  