Re: Mother of all Variants

From: Alexander Grund (alexander.grund_at_[hidden])
Date: 2019-06-28 06:44:26

Am 28.06.19 um 06:40 schrieb Gavin Lambert via Boost:
> On 28/06/2019 16:12, David Sankel wrote:
>> Many would prefer their PIMPL classes to not have an artificial
>> empty/partially formed state because of the increased semantic 
>> complexity
>> that implies.
>
> Maybe, but that seems a bit daft to me. 
Agreed. The increased complexity doesn't exist if you consider a 
moved-from object as invalid. You can either have a raw nullptr or an 
empty unique_ptr or an unchanged shared_ptr. Neither of them will even 
add a single additional check to the code base. At the very maximum you 
need 1 more check in the destructor if your PIMPL is some kind of 
interface handle-like which cannot be freed if it is "null" (whatever 
this means for that). Example would be INVALID_HANDLE for files and such.