Re: [Boost-users] [Spirit] dereferencing type-punned pointer will break strict-aliasing rules

Subject: Re: [Boost-users] [Spirit] dereferencing type-punned pointer will break strict-aliasing rules
From: Joel de Guzman (joel_at_[hidden])
Date: 2010-08-12 00:05:01

On 8/12/10 2:59 AM, Emil Dotchevski wrote:
> On Wed, Aug 11, 2010 at 1:37 AM, Roland Bock<rbock_at_[hidden]>  wrote:
>> Hi,
>>
>> compiling the attached example with gcc-4.4.3 (Ubuntu 10.4, 64bit) with
>>
>> -Wall -O3
>>
>> leads to a long warning message (second attachment), culminating in
>>
>> boost/1.44/include/boost/function/function_base.hpp:321: warning:
>> dereferencing type-punned pointer will break strict-aliasing rules
>> boost/1.44/include/boost/function/function_base.hpp:325: warning:
>> dereferencing type-punned pointer will break strict-aliasing rules
>>
>>
>> I wonder how I could avoid this without -fno-strict-aliasing or
>> -Wno-strict-aliasing?
>
> The code in question is a reinterpret_cast which casts a char pointer
> to a user-specified functor type pointer. The interpret cast seems
> correct, and the warning seems correct too if not very useful in this
> case.

Shouldn't this thread have a [function] subject as this seems to be
about boost.function issue?

Regards,
-- 
Joel de Guzman
http://www.boostpro.com
http://spirit.sf.net