On Fri, Feb 20, 2015 at 12:06:28PM +0100, Florian Weimer wrote:
> On 02/19/2015 09:56 PM, Sandra Loosemore wrote:
> > Hmmmm, Passing the additional option in user code would be one thing,
> > but what about library code? E.g., using memcpy (either explicitly or
> > implicitly for a structure copy)?
>
> The memcpy problem isn't restricted to embedded architectures.
>
> size_t size;
> const unsigned char *source;
> std::vector<char> vec;
> …
> vec.resize(size);
> memcpy(vec.data(), source, size);
>
> std::vector<T>::data() can return a null pointer if the vector is empty,
> which means that this code is invalid for empty inputs.
>
> I think the C standard is wrong here. We should extend it, as a QoI
> matter, and support null pointers for variable-length inputs and outputs
> if the size is 0. But I suspect this is still a minority view.
I disagree. If you want a function that will have that different property,
don't call it memcpy.
Jakub
