diff -r be505d22dde8 Modules/_testbuffer.c
--- a/Modules/_testbuffer.c	Thu Aug 30 00:30:14 2012 +0200
+++ b/Modules/_testbuffer.c	Thu Aug 30 13:23:01 2012 -0400
@@ -5,7 +5,7 @@
 #define PY_SSIZE_T_CLEAN
 
 #include "Python.h"
-
+#include <stddef.h>
 
 /* struct module */
 PyObject *structmodule = NULL;
@@ -2784,6 +2784,150 @@
 };
 
 
+static int
+congruent(Py_buffer *v1, Py_buffer *v2)
+{
+    return v1->len == v2->len &&
+        v1->ndim == v2->ndim &&
+        v1->readonly == v2->readonly &&
+        v1->itemsize == v2->itemsize &&
+        strcpy(v1->format, v2->format) == 0 &&
+        memcpy(v1->shape, v2->shape, v1->ndim) == 0 &&
+        memcpy(v1->strides, v2->strides, v1->ndim) == 0 &&
+        memcpy(v1->suboffsets, v2->suboffsets, v1->ndim) == 0;
+}
+
+static PyObject *
+objview_bytes(PyObject *obj, Py_ssize_t *outer_suboffset)
+{
+    PyObject *view;
+    Py_buffer info;
+
+    *outer_suboffset = offsetof(PyBytesObject, ob_sval);
+    if (PyObject_GetBuffer(obj, &info, PyBUF_FULL_RO) < 0)
+	return NULL;
+    assert(info.buf == *outer_suboffset + (char *)obj);
+    info.buf = (char *)obj;
+    view = PyMemoryView_FromBuffer(&info);
+
+    return view;
+}
+
+static PyObject *
+objview_array(PyObject *obj, Py_ssize_t *outer_suboffset)
+{
+    typedef struct {
+        PyObject_VAR_HEAD
+        char *ob_item;
+    } arrayobject_head;
+    Py_ssize_t shape[2] = {1,};
+    Py_ssize_t strides[2] = {sizeof(char*),};
+    Py_ssize_t suboffsets[2] = {0, -1};
+    PyObject *view;
+    Py_buffer info;
+    *outer_suboffset = offsetof(arrayobject_head, ob_item);
+    if (PyObject_GetBuffer(obj, &info, PyBUF_FULL_RO) < 0)
+	return NULL;
+    assert(info.buf == *(char **)(*outer_suboffset + (char *)obj));
+    info.buf = (char *)obj;
+    info.ndim = 2;
+    shape[1] = info.len;
+    info.shape = shape;
+    strides[1] = info.itemsize;
+    info.strides = strides;
+    info.suboffsets = suboffsets;
+    view = PyMemoryView_FromBuffer(&info);
+
+    return view;
+}
+
+static PyObject *
+objview_tuple(PyObject *tup, Py_ssize_t *outer_suboffset);
+
+static PyObject *
+objview_any(PyObject *obj, Py_ssize_t *outer_suboffset)
+{
+    if (PyTuple_Check(obj))
+        return objview_tuple(obj, outer_suboffset);
+    if (PyBytes_Check(obj))
+        return objview_bytes(obj, outer_suboffset);
+    /* XXX need a more robust check */
+    if (strcmp("array.array", Py_TYPE(obj)->tp_name) == 0)
+        return objview_array(obj, outer_suboffset);
+    PyErr_Format(PyExc_TypeError, "unsupported type");
+    return NULL;
+}
+
+static PyObject *
+objview_tuple(PyObject *tup, Py_ssize_t *outer_suboffset)
+{
+    typedef struct {
+        PyObject_VAR_HEAD
+        char *ob_item;
+    } arrayobject_head;
+    PyObject *view;
+    PyObject *obj;
+    Py_buffer info;
+    PyMemoryViewObject *subview;
+    Py_ssize_t i, *sizes, suboffset0;
+    *outer_suboffset = offsetof(PyTupleObject, ob_item);
+    obj = PyTuple_GET_ITEM(tup, 0);
+    subview = (PyMemoryViewObject *)objview_any(obj, &suboffset0);
+    /* XXX add congruency check */
+    if (subview == NULL)
+        return NULL;
+    Py_INCREF(tup); 
+       info.obj = tup;
+    info.buf = &PyTuple_GET_ITEM(tup, 0);
+    assert(*outer_suboffset + (char *)tup == info.buf);
+    info.len = PyTuple_GET_SIZE(tup) * subview->view.len;
+    info.ndim = 1 + subview->view.ndim;
+    info.itemsize = subview->view.itemsize;
+    info.format = subview->view.format;
+    info.readonly = subview->view.readonly;
+    sizes = PyMem_Malloc(3 * info.ndim * sizeof(Py_ssize_t));
+    if (sizes == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    info.shape = sizes;
+    info.strides = sizes + info.ndim;
+    info.suboffsets = sizes + 2 * info.ndim;
+    info.shape[0] = PyTuple_GET_SIZE(tup);
+    for (i = 0; i < subview->view.ndim; ++i)
+        info.shape[1 + i] = subview->view.shape[i];
+    info.strides[0] = sizeof(PyObject *);
+    for (i = 0; i < subview->view.ndim; ++i)
+        info.strides[1 + i] = subview->view.strides[i];
+    info.suboffsets[0] = suboffset0;
+    if (subview->view.suboffsets == NULL)
+        for (i = 0; i < subview->view.ndim; ++i)
+            info.suboffsets[1 + i] = -1;
+    else
+        for (i = 0; i < subview->view.ndim; ++i)
+            info.suboffsets[1 + i] = subview->view.suboffsets[i];
+    view = PyMemoryView_FromBuffer(&info);
+    /* PyMemoryView_FromBuffer ignores info.buf.  Add it explicitely. */
+    if (view != NULL)
+      ((PyMemoryViewObject *)view)->view.obj = info.obj;
+    PyMem_Free(sizes);
+    Py_DECREF(subview);
+    return view;
+}
+
+
+PyDoc_STRVAR(objview_doc,
+"objview(obj)\n\
+\n\
+Return a memoryview with buf = obj");
+
+static PyObject *
+objview(PyObject *self, PyObject *obj)
+{
+    Py_ssize_t dummy;
+    return objview_any(obj, &dummy);
+}
+
 static struct PyMethodDef _testbuffer_functions[] = {
     {"slice_indices", slice_indices, METH_VARARGS, NULL},
     {"get_pointer", get_pointer, METH_VARARGS, NULL},
@@ -2792,6 +2936,7 @@
     {"py_buffer_to_contiguous", py_buffer_to_contiguous, METH_VARARGS, NULL},
     {"is_contiguous", is_contiguous, METH_VARARGS, NULL},
     {"cmp_contig", cmp_contig, METH_VARARGS, NULL},
+    {"objview", objview, METH_O, objview_doc},
     {NULL, NULL}
 };