1318a1319,1507
> static PyObject *
> builtin_minmax(PyObject *self, PyObject *args, PyObject *kwds)
> {
> 	const char *name = "minmax";
> 	PyObject *v, *it, *item, *val, *item2, *val2, *minitem, *minval, *maxitem, *maxval, *keyfunc=NULL;
> 	PyObject *result = NULL;
> 	int seqlen, cmp;
> 
> 	if (PyTuple_Size(args) > 1)
> 		v = args;
> 	else if (!PyArg_UnpackTuple(args, (char *)name, 1, 1, &v))
> 		return NULL;
> 
> 	if (kwds != NULL && PyDict_Check(kwds) && PyDict_Size(kwds)) {
> 		keyfunc = PyDict_GetItemString(kwds, "key");
> 		if (PyDict_Size(kwds)!=1  ||  keyfunc == NULL) {
> 			PyErr_Format(PyExc_TypeError,
> 				"%s() got an unexpected keyword argument", name);
> 			return NULL;
> 		}
> 		Py_INCREF(keyfunc);
> 	}
> 
> 	it = PyObject_GetIter(v);
> 	if (it == NULL) {
> 		Py_XDECREF(keyfunc);
> 		return NULL;
> 	}
> 
> 	minitem = NULL; /* the results */
> 	maxitem = NULL; 
> 	minval = NULL;  /* the values associated with the results */
> 	maxval = NULL;  
> 
> 	/* initialize min and max returns with the first item in the list */
> 	item = PyIter_Next(it);
> 	if (item == NULL)
> 	{
> 		//minitem = Py_None;
> 		//Py_INCREF(minitem);
> 		//maxitem = Py_None;
> 		//Py_INCREF(maxitem);
> 		goto EarlyExit_short_sequence;
> 	}
> 
> 	if (keyfunc != NULL) {
> 		val = PyObject_CallFunctionObjArgs(keyfunc, item, NULL);
> 		if (val == NULL)
> 			goto Fail_it_item;
> 	}
> 	/* no key function; the value is the item */
> 	else {
> 		val = item;
> 		// increment twice, as we will assign to both min and max return vals
> 		Py_INCREF(val);
> 		Py_INCREF(val);
> 	}
> 
> 	minitem = item;
> 	minval = val;
> 	maxitem = item; /* the result */
> 	maxval = val;  /* the value associated with the result */
> 
> 	seqlen = PySequence_Length(v);
> 	
> 	// if even length sequence, put iter back at 0, to safely read by pairs
> 	if (seqlen % 2 == 0) {
> 		it = PyObject_GetIter(v);
> 	}
> 
> 	// read by pairs
> 	while (( item = PyIter_Next(it) ) && (item2 = PyIter_Next(it))) {
> 
> 		/* get the value from the key function */
> 		if (keyfunc != NULL) {
> 			val  = PyObject_CallFunctionObjArgs(keyfunc, item, NULL);
> 			val2 = PyObject_CallFunctionObjArgs(keyfunc, item2, NULL);
> 			if (val == NULL || val2 == NULL)
> 				goto Fail_it_item;
> 		}
> 		/* no key function; the value is the item */
> 		else {
> 			val = item;
> 			Py_INCREF(val);
> 			val2 = item2;
> 			Py_INCREF(val2);
> 		}
> 
> 
> 		/*
>         if a > b:
>             a,b = b,a
> 		*/
> 		cmp = PyObject_RichCompareBool(val, val2, Py_GT);
> 		if (cmp < 0)
> 			goto Fail_it_item_and_val;
> 		else if (cmp > 0) {
> 			PyObject* tmp;
> 			tmp = val;  val  = val2;  val2  = tmp;
> 			tmp = item; item = item2; item2 = tmp;
> 		}
> 
> 		/*
>         if a < min_:
>             min_ = a
> 		*/
> 		cmp = PyObject_RichCompareBool(val, minval, Py_LT);
> 		if (cmp < 0)
> 			goto Fail_it_item_and_val;
> 		else if (cmp > 0) {
> 			Py_DECREF(minval);
> 			Py_DECREF(minitem);
> 			minval = val;
> 			minitem = item;
> 		}
> 		else {
> 			Py_DECREF(item);
> 			Py_DECREF(val);
> 		}
> 
> 		/*
>         if b > max_:
>             max_ = b
> 		*/
> 		cmp = PyObject_RichCompareBool(val2, maxval, Py_GT);
> 		if (cmp < 0)
> 			goto Fail_it_item_and_val;
> 		else if (cmp > 0) {
> 			Py_DECREF(maxval);
> 			Py_DECREF(maxitem);
> 			maxval = val2;
> 			maxitem = item2;
> 		}
> 		else {
> 			Py_DECREF(item2);
> 			Py_DECREF(val2);
> 		}
> 	}
> 	if (PyErr_Occurred())
> 		goto Fail_it;
> 
> EarlyExit_short_sequence:
> 	if (maxval == NULL) {
> 		PyErr_Format(PyExc_ValueError,
> 			     "%s() arg is an empty sequence", name);
> 		assert(maxitem == NULL);
> 	}
> 	else {
> 		Py_DECREF(maxval);
> 		Py_DECREF(minval);
> 	}
> 	Py_DECREF(it);
> 	Py_XDECREF(keyfunc);
> 
> 	if (maxitem != NULL) {
> 		result = PyTuple_Pack(2, minitem, maxitem);
> 		Py_DECREF(minitem);
> 		Py_DECREF(maxitem);
> 	}
> 	else {
> 		result = NULL;
> 	}
> 
> 	return result;
> 
> Fail_it_item_and_val:
> 	Py_DECREF(val);
> 	Py_DECREF(val2);
> Fail_it_item:
> 	Py_DECREF(item);
> 	Py_DECREF(item2);
> Fail_it:
> 	Py_XDECREF(minval);
> 	Py_XDECREF(minitem);
> 	Py_XDECREF(maxval);
> 	Py_XDECREF(maxitem);
> 	Py_DECREF(it);
> 	Py_XDECREF(keyfunc);
> 	return NULL;
> }
> 
> PyDoc_STRVAR(minmax_doc,
> "minmax(iterable[, key=func]) -> value\n\
> minmax(a, b, c, ...[, key=func]) -> value\n\
> \n\
> With a single iterable argument, return its smallest and largest items.\n\
> With two or more arguments, return the smallest and largest arguments.");
> 
> 
2265a2455
>  	{"minmax",		(PyCFunction)builtin_minmax,        METH_VARARGS | METH_KEYWORDS, minmax_doc},