add comment about __array_prepare__ to 1.4 release notes

2 files changed, 27 insertions, 2 deletions

diff --git a/numpy/core/src/multiarray/methods.c b/numpy/core/src/multiarray/methods.c
index de99ca137..8ec256105 100644
--- a/numpy/core/src/multiarray/methods.c
+++ b/numpy/core/src/multiarray/methods.c
@@ -756,6 +756,31 @@ array_cast(PyArrayObject *self, PyObject *args)
 
 
 static PyObject *
+array_preparearray(PyArrayObject *self, PyObject *args)
+{
+    PyObject *arr;
+    PyObject *ret;
+
+    if (PyTuple_Size(args) < 1) {
+        PyErr_SetString(PyExc_TypeError,
+                        "only accepts 1 argument");
+        return NULL;
+    }
+    arr = PyTuple_GET_ITEM(args, 0);
+    if (arr == NULL) {
+        return NULL;
+    }
+    if (!PyArray_Check(arr)) {
+        PyErr_SetString(PyExc_TypeError,
+                        "can only be called with ndarray object");
+        return NULL;
+    }
+    Py_INCREF(arr);
+    return arr;
+}
+
+
+static PyObject *
 array_wraparray(PyArrayObject *self, PyObject *args)
 {
     PyObject *arr;
diff --git a/numpy/doc/subclassing.py b/numpy/doc/subclassing.py
index 5f658d922..24f0108d7 100644
--- a/numpy/doc/subclassing.py
+++ b/numpy/doc/subclassing.py
@@ -420,8 +420,8 @@ So:
 
 .. _array-wrap:
 
-``__array_wrap__`` for ufuncs
------------------------------
+``__array_prepare__`` and ``__array_wrap__`` for ufuncs
+-------------------------------------------------------
 
 ``__array_wrap__`` gets called at the end of numpy ufuncs and other numpy
 functions, to allow a subclass to set the type of the return value