[Patch] libstdc++/25626: valarray vs non-POD

[Paolo Carlini]

Gabriel Dos Reis wrote:
> I much prefer the use of __values().
>   
Honestly, I don't, for various reasons, and, not hearing from you, 
already committed the last patch.

Among the reasons, we end up with both friendship of _Array and 
__values() in valarray (we cannot change the type of the _M_array member 
of valarray for ABI reasons, sorry for not clearly explaining that); 
inconsistency among the various constructors about the use/not use of 
_Array. Also, not secondary, I trust the last version much more because 
uses completely for the real work existing facilities and calling 
conventions, in a way completely consistent with the rest of the 
library: add maybe a minimum of clean-up and someone coming from the 
outside would not even imagine we had the bug, at some point. I would 
leave to you, much more knowledgeable in this area, further 
improvements... Only, as we already discussed, let's agree in advance 
about binary compatibility breakages...

Thanks,
Paolo.