text: #ifndef CRCX__CDEFS_H_
  #define CRCX__CDEFS_H_
  
  #ifdef __cplusplus
  #define __BEGIN_DECLS extern "C" {
  #define __END_DECLS }
  #else
  #define __BEGIN_DECLS
  #define __END_DECLS
  #endif /* __cplusplus */
  
  #endif /* CRCX__CDEFS_H_ */