1 files changed, 41 insertions, 14 deletions

diff --git a/numpy/core/src/arrayobject.c b/numpy/core/src/arrayobject.c
index 9fdc67ee5..9fbffb3c3 100644
--- a/numpy/core/src/arrayobject.c
+++ b/numpy/core/src/arrayobject.c
@@ -6101,7 +6101,8 @@ PyArray_ValidType(int type)
 /* If the output is not a CARRAY, then it is buffered also */
 
 static int
-_bufferedcast(PyArrayObject *out, PyArrayObject *in)
+_bufferedcast(PyArrayObject *out, PyArrayObject *in, 
+	      PyArray_VectorUnaryFunc *castfunc)
 {
 	char *inbuffer, *bptr, *optr;
 	char *outbuffer=NULL;
@@ -6114,12 +6115,10 @@ _bufferedcast(PyArrayObject *out, PyArrayObject *in)
 	int inswap, outswap=0;
 	int obuf=!PyArray_ISCARRAY(out);
 	int oelsize = out->descr->elsize;
-	PyArray_VectorUnaryFunc *castfunc;
         PyArray_CopySwapFunc *in_csn;
         PyArray_CopySwapFunc *out_csn;
 	int retval = -1;
 
-	castfunc = in->descr->f->cast[out->descr->type_num];
         in_csn = in->descr->f->copyswap;
         out_csn = out->descr->f->copyswap;
 
@@ -6252,6 +6251,39 @@ PyArray_CastToType(PyArrayObject *mp, PyArray_Descr *at, int fortran)
 
 }
 
+/*OBJECT_API
+   Get a cast function to cast from the input descriptor to the 
+   output type_number (must be a registered data-type).
+   Returns NULL if un-successful. 
+*/
+static PyArray_VectorUnaryFunc *
+PyArray_GetCastFunc(PyArray_Descr *descr, int type_num)
+{
+	PyArray_VectorUnaryFunc *castfunc;
+	if (type_num >= PyArray_NTYPES) {
+		PyObject *obj = descr->f->castdict;
+		if (obj && PyDict_Check(obj)) {
+			PyObject *key;
+			PyObject *cobj;
+			key = PyInt_FromLong(type_num);
+			cobj = PyDict_GetItem(obj, key);
+			Py_DECREF(key);
+			if (PyCObject_Check(cobj)) {
+				castfunc = PyCObject_AsVoidPtr(cobj);
+			}
+		}
+	}
+	else {
+		castfunc = descr->f->cast[type_num];
+	}
+
+	if (castfunc) return castfunc;
+
+	PyErr_SetString(PyExc_ValueError,
+			"No cast function available.");
+	return NULL; 
+}
+
 /* The number of elements in out must be an integer multiple
    of the number of elements in mp.
 */
@@ -6266,6 +6298,7 @@ PyArray_CastTo(PyArrayObject *out, PyArrayObject *mp)
 	int simple;
 	intp mpsize = PyArray_SIZE(mp);
 	intp outsize = PyArray_SIZE(out);
+	PyArray_VectorUnaryFunc *castfunc=NULL;
 
 	if (mpsize == 0) return 0;
 	if (!PyArray_ISWRITEABLE(out)) {
@@ -6281,12 +6314,9 @@ PyArray_CastTo(PyArrayObject *out, PyArrayObject *mp)
 		return -1;
 	}
 
-	if (out->descr->type_num >= PyArray_NTYPES) {
-		PyErr_SetString(PyExc_ValueError,
-				"Can only cast to builtin types.");
-		return -1;
-
-	}
+	castfunc = PyArray_GetCastFunc(mp->descr, out->descr->type_num);
+		
+	if (castfunc == NULL) return -1;
 
 	simple =  ((PyArray_ISCARRAY_RO(mp) && PyArray_ISCARRAY(out)) ||   \
                    (PyArray_ISFARRAY_RO(mp) && PyArray_ISFARRAY(out)));
@@ -6299,17 +6329,14 @@ PyArray_CastTo(PyArrayObject *out, PyArrayObject *mp)
 
 		while(ncopies--) {
 			inptr = mp->data;
-			mp->descr->f->cast[out->descr->type_num](inptr,
-							      optr,
-							      mpsize,
-							      mp, out);
+			castfunc(inptr, optr, mpsize, mp, out);
 			optr += obytes;
 		}
 		return 0;
 	}
 
 	/* If not a well-behaved cast, then use buffers */
-	if (_bufferedcast(out, mp) == -1) {
+	if (_bufferedcast(out, mp, castfunc) == -1) {
 		return -1;
 	}
 	return 0;