[C++-sig] boost/python 1.33.1 breaks aliasing rules

David Abrahams dave at boost-consulting.com
Sat Jun 24 15:21:56 CEST 2006

"Ralf W. Grosse-Kunstleve" <rwgk at yahoo.com> writes:

> Coincidentally, on Python-Dev Scott David Daniels just suggested this trick to
> get rid of the "will break strict-aliasing rules" warnings:
>>     PyObject_CallFunction((PyObject*) (void *) &PyRange_Type,
>>                           "lll", start, start+len*step, step)
> I.e. the trick is to insert an intermediate (void *) cast. It works with g++
> 4.1.0 at least. Could this be a general solution?

There's no such thing as a general solution to a warning (they're
implementation specific), and these "strict aliasing rules" are a C99
thing, and C++ is based on C89 (or C90, I forget which), and the code
above does the so it's hard to say what should be done.

Maybe reading
would help.

Dave Abrahams
Boost Consulting

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