On 22/09/2010 20:05, Larry Evans wrote:
I thought variant just static_cast<char*> to void* then from void* to T*.
As far as I'm concerned, this is the same thing.
The char* is for the memory buffer in boost::aligned_storage. IOW, it doesn't use reinterpret_cast. To confirm, I did:
find . -name \*.hpp -exec grep _cast {} \; -ls
in boost/variant and only found static_cast.
Now, as far as Frank's point about operator=, my reply to his post indicated there would never be a case where two pointers of different types and pointing to the same memory location would be in scope at the same time in the operator= implementation, at least for the container_one_of_maybe mentioned in my reply. I don't know if that is true for boost::variant.
A first try is to ask GCC if you break the strict aliasing rules. Compile some test code with -O3 -Wstrict-aliasing and see if it says something.