[NumPy-Tickets] [NumPy] #1612: Alignment don't work in subarrays

[NumPy Trac]

#1612: Alignment don't work in subarrays
---------------------------------------------------+------------------------
 Reporter:  Ihor.Melnyk                            |       Owner:  somebody
     Type:  defect                                 |      Status:  new     
 Priority:  highest                                |   Milestone:  2.0.0   
Component:  numpy.core                             |     Version:  devel   
 Keywords:  multiarray alignment padding subarray  |  
---------------------------------------------------+------------------------
 Specifying alignment in dtype specification does not work (alignment
 should be 4 in both cases):

 {{{
 >>> t = np.dtype('1i4', align=True)
 >>> t.alignment
 4
 >>> t = np.dtype('2i4', align=True)
 >>> t.alignment
 1
 }}}


 This is critical to ensure that NPY binary data matches exactly complex
 structures defined in C.

 Proposed solution



 {{{


 Index: descriptor.c
 ===================================================================
 --- descriptor.c        (revision 8715)
 +++ descriptor.c        (working copy)
 @@ -254,6 +254,7 @@
          newdescr->subarray = _pya_malloc(sizeof(PyArray_ArrayDescr));
          newdescr->subarray->base = type;
          newdescr->flags = type->flags;
 +        newdescr->alignment = type->alignment;
          Py_INCREF(val);
          newdescr->subarray->shape = val;
          Py_XDECREF(newdescr->fields);
 }}}

-- 
Ticket URL: <http://projects.scipy.org/numpy/ticket/1612>
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