result = __tfind (&key, known_derivations, derivation_compare);
result = __tfind (&key, &known_derivations, derivation_compare);
derivation_lookup (const char *fromset, const char *toset,		   struct gconv_step **handle, size_t *nsteps){  struct known_derivation key = { fromset, toset, NULL, 0 };  struct known_derivation *result;  result = __tfind (&key, known_derivations, derivation_compare);  if (result == NULL)    return GCONV_NOCONV;  *handle = result->steps;  *nsteps = result->nsteps;  /* Please note that we return GCONV_OK even if the last search for     this transformation was unsuccessful.  */  return GCONV_OK;}