Testing parallel mode and PR34106

[Paolo Carlini]

Paolo Carlini wrote:
> Chris Jefferson wrote:
>   
>> I haven't looked at this example, but I've previously had trouble with
>> vector<bool> in threaded code. You can't assume you can read and write
>> to distinct values in different threads, because of how the different
>> bits are compressed together.
>>     
> Interesting observation, in any case. Thanks,
>
>   
... but the present issue is at *compile* time ;)

Paolo.