Trying to make sense of the [basic.lifetime] section of the standard, but it appears to be contradictive in a few places.
While I'm generally I'm aware that there is work still going on to further improve the standard, there is one particular contradiction that I haven't seen covered. http://eel.is/c++draft/basic#life-8 places restrictions in case the object lifetime ended but *
before* the storage has been *
released* or *
re-used*. While mentioning *
released* makes sense, *
re-used*, in my opinion, brings contradiction since most often the new object would be created using placement new, and now the latest standard does clearly mention that storage is first released in placement new, and then the new object is created [
http://eel.is/c++draft/basic#life-1.5]
Wouldn't the drop of *
re-used* from
http://eel.is/c++draft/basic#life-8 make it non-contradictive? My reasoning is that as *
re-used* is defined at least for placement new (maybe
memcpy as well?) the following code from the example in [basic.life]#8
this->~C(); // lifetime of *this ends
new (this) C(other); // new object of type C created. But why storage is not considered re-used given new rules in [basic.life]#1 around placement new
would imply the following sequence of ordered events
(1) end of a lifetime for the object which this used to point to ->
(2) storage which this used to to point is *re-used* [basic.life]#1 ->
(3) new object C is created at the storage which is used to point to
Then if the above is correct, the condition is in [basic.life]#8 cannot apply to the corresponding example as (1) happens before (2) and (2) happens before (3). Now if (2) would have been dropped as the required condition then it would all make sense. However looks like from the comment in the example above, that the standard omits *re-use* in "new (this) C(other"
Any thoughts on this? Or I've missed some important piece in my reasoning?
Kind Regards,
Mykola