[Python-Dev] INPLACE_ADD and INPLACE_MULTIPLY oddities in ceval.c

[Guido van Rossum]

On 3/29/06, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Tim Hochberg wrote:
>
> > Still, perhaps for Py3K it's worth considering
> > if PyNumber_InplaceAdd should only call __iadd__ and __add__, not
> > __radd__. Thus giving the target object complete control during inplace
> > adds.
>
> That's probably reasonable, although it would break
> the conceptual notion that a += b is equivalent to
> a = a + b when a can't be modified in-place.

No, it's not reasonable, because this would fail:

x = 5
x += 0.5

--
--Guido van Rossum (home page: http://www.python.org/~guido/)