Collective operations are being used by several parallel language like MPI or openMP
{{{  
// Operation for collective reductions or collective operations
typedef enum {
  NO_OP,    // no operation
  MAX,      // maxinum
  MIN,      // minimun
  SUM,      // sum
  PROD,     // product
  LAND,     // logical and
  BAND,     // bit-wise and
  LOR,      // logical or
  BOR,      // bit-wise or
  LXOR,     // logical exclusive or
  BXOR,     // bit-wise exclusive or
  MINLOC,   // min value and location
  MAXLOC,   // max value and location
  REPLACE   // replace ? TODO: Find definition for this operation
}$operation;
}}}

An system function being responsible for doing the operation will be much helpful for implementing collective function like "MPI_Reduce()".
{{{
/* Unpacks the bundle type data and applays the specified operations on that data.
   For every binary operarions defined in &operation, data will be used as the left operand and 
   buf will be used as right operand and input and ouput argument. The value of buf as an input
   argument will always be the result got from the very last operation. Finally buf is also an output argument.
*/
void $bundle_unpack_apply(void *data, void *buf, int size, $operation op);
}}}