Mark Mitchell wrote: > Will the UK committee open a DR for this? Or, would you care to send > mail to Steve Adamczyk about it? this can be done. I shall wait until the minutes have been written up.
> >> The observation was made that if A is non-POD, one cannot play offsetof >> tricks to get from A::a to A::b, so the optimization is safe on non-PODs. >> (Of course one would have to prove the address of 'v' did not escape, >> so I guess the ctor and dtor would need to be trivial or visible.) > > > I argued last week that this was not in fact true, in that you can do: > > ptrdiff_t x = &v.b - &v.a; > > and then use that instead of "offsetof (Foo, b) - offsetof (Foo, a)". Does not '&v.b - &v.a' cause the address to 'escape', and therefore lock down the structure? If it doesn't, how hard would it be to make that DTRT? nathan -- Nathan Sidwell :: http://www.codesourcery.com :: CodeSourcery LLC [EMAIL PROTECTED] :: http://www.planetfall.pwp.blueyonder.co.uk
