rvalue references

[Diggory]

On Wednesday, 24 April 2013 at 00:54:12 UTC, kenji hara wrote:
> 2013/4/24 Manu <turkeyman at gmail.com>
>
>> "The r-value being passed is assigned to a stack allocated 
>> temporary,
>> which has a lifetime that is identical to any other local 
>> variable, ie, the
>> lifetime of the function in which it appears."
>> There, I defined it.
>>
>
> Good definition. If add more,
> "getting address of "scope" parameter would be disallowed, at 
> least in
> @safe code, because it would be regarded as the escape of stack 
> allocated
> temporary."
>
> Kenji Hara

Why does the temporary need to exist any longer than the current 
statement? (the current lifetime of temporaries are the statement 
or expression). Surely any longer is just wasting stack space.