On 31 March 2014 18:18, Walter Bright <newshound2@digitalmars.com> wrote:

On 3/30/2014 7:10 PM, Manu wrote:

On 31 March 2014 11:39, bearophile <bearophileHUGS@lycos.com
<mailto:bearophileHUGS@lycos.com>> wrote:

Manu:

The most annoying thing about a hidden vtable pointer is it breaks
alignment.

D class instances have two hidden fields.

Oh yeah... well that loses a lot of appeal from me in that case ;)

On 64 bits, the two fields means the rest starts at 16 byte alignment - ideal for SIMD!

Most computers aren't 64bit though. The fact that the pointers change in size between platforms is a huge nuisance. I often find I end up with some very annoying #ifdef's at the start of tightly packed classes to deal with this issue in C++.