[boost] Re: unions

From: Eric Friedman (ebf_at_[hidden])
Date: 2003-10-07 20:54:00

E. Gladyshev wrote:

> --- Eric Friedman <ebf_at_[hidden]> wrote:
> 
>>In my opinion, the ability to turn off heap backup for variant should be 
>>seen as an optimization (i.e., as it prevents costly heap allocation) 
>>and not any sort of interface feature. Please disagree with me though.
> 
> 
> The problem is that the user might turn no/off the heap 
> backup inadvertently by simple specifying an 'int' 
> as the first type. So in generic context, the variant 
> protection (with the heap backup) is unpredictable.
> 
> Eugene

Some questions:

* Heap backup is on by default. Why would it matter if the user 
inadvertently turns it off?

* What exactly do you mean by "variant protection"? The reason heap 
backup can be turned off in certain cases is because it is *not needed* 
in those cases. The guarantees made by variant are always the same.

Eric