Function find_enumitem

src/backend/utils/cache/typcache.c:2783–2795

* Locate the EnumItem with the given OID, if present */

 * Locate the EnumItem with the given OID, if present
 */
static EnumItem *
find_enumitem(TypeCacheEnumData *enumdata, Oid arg)
{
	EnumItem	srch;

	/* On some versions of Solaris, bsearch of zero items dumps core */
	if (enumdata->num_values <= 0)
		return NULL;

	srch.enum_oid = arg;
	return bsearch(&srch, enumdata->enum_values, enumdata->num_values,
				   sizeof(EnumItem), enum_oid_cmp);
}

/*
 * qsort comparison function for OID-ordered EnumItems