DMD optimization bug?

[Dmitry Olshansky]

22-Mar-2013 13:01, Jacob Carlborg пишет:
> On 2013-03-22 09:14, Dmitry Olshansky wrote:
>
>> OK so c points to [1, 2, 3, 4, 5] (and who knows if it's 5 bytes or 5
>> ints) slice. *c is that slice, (cast(int[])*c)[1..3] is pieces of that
>> slice an r-value.
>> Mmm so you are returning a pointer to r-value (a local temporary)?
>> What's the point of the code?
>
> I'm showing here a reduced minimal test case, that's why it looks
> strange. The full source code is here:
>

It doesn't change the fact that pointer to slice is not going to work. 
Esp pointer to stack-allocated slice. You'll get garbage and sometimes 
segfaults.

What's wrong with returning slice by value ?

> https://github.com/jacob-carlborg/orange/blob/master/orange/serialization/Serializer.d#L1672
>
Exactly what you describe there is not going to work at all. Taking 
address of temporary slice (a[x..y] is a temporary value) is welcoming a 
segfault.



-- 
Dmitry Olshansky