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

On Thu, Aug 12, 2010 at 12:48 AM, Roland Bock wrote:

On 08/12/2010 08:26 AM, KSpam wrote:

...

Roland,

On Wednesday 11 August 2010 01:37:17 Roland Bock wrote:

...

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

This warning can be prevented by splitting the line into two lines as follows:

Replace: reinterpret_cast(&in_buffer.data)->~Functor();

with: functor_type* p = reinterpret_cast(&in_buffer.data); p->~Functor();

I patched my local version of Boost in order to prevent these warnings.

Hope This Helps, Justin

Justin,

thanks for the hint! I'll give it a try and will probably file a ticket if it works out :-)

Also, you should file a ticket with GCC, two tickets actually: 1) a trivial change like this should not have effect on the warning, and 2) strict aliasing rules should not apply to char pointers (as far as I can tell, in_buffer.data is of char type specifically to deal with this issue.) Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode