"ian at airs dot com" <[EMAIL PROTECTED]> writes: | I'm not sure what to make of comment #84. We don't determine aliasing by | alignment or size. We determine it by type. We don't currently treat int and | long as aliasing each other even if they happen to have the same alignment and | size.
That is GOOD. :-) | I believe this is correct according to the C standard but I am less | familiar with the C++ standard. It is also correct semantics with respect to C++. C++ goes further (I don't have C standard handy to check). The memory pointed to by p must have the "right" alignment requirements etc. So if you grab memory into p and it does not have the right alignment, then the new placement yields undefined behaviour. That is not a property we can check statically (until we get the alignment proposal into C++). | We could change the aliasing machinery in that | way for C++ if it seems to be appropriate, but I would prefer to take that to a | different PR. What I was trying to say was that C++ provides the same "dynamic type" (non-)aliasing guarantees, and goes even further. Did I manage to confuse you again? -- Gaby
