dip1000 and preview in combine to cause extra safety errors

[forkit]

On Tuesday, 14 June 2022 at 07:34:29 UTC, Paulo Pinto wrote:
>
> The compiler removed it, as you aren't using it,  naturally it 
> looks the same.
>
> Now tell the compiler not to be smart helping you,
>
> https://d.godbolt.org/z/fY14oz86E

I expect the compiler to be smart in helping me ;-)

In yet another example, the argument that 'less instructions are 
needed to allocate on the heap vs the stack', does not hold up to 
further scrutiny (at least in this optimised example).

https://d.godbolt.org/z/E85hWrocM

Presumably, the more complex the type of allocation be requested, 
the more difficult it is for the optimiser to optimise that 
request, and so you do in fact end up with more instructions for 
heap allocation. That is the only explanation I can come up with 
;-)

But i leave further analysis to another thread ;-)