```
Python 2.7.3 (default, Sep  9 2012, 20:37:57) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import galsim
>>> im = galsim.Image(5,5)
>>> im_const = im.view(make_const=True)
>>> im_const.setValue(2,3, 1.234)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "galsim/image.py", line 465, in setValue
    self.image.setValue(pos.x, pos.y, value)
AttributeError: 'ConstImageViewF' object has no attribute 'setValue'
```
It seems relatively clear.  Do you think it's worth catching this and rewording?