[Patch/RFA] libstdc++/21554

[Benjamin Kosnik]

> ok, attributes don't work with dependent expressions 

still a bummer

>and, moreover, the alignment attribute doesn't work with typedefs, 

ditto

>but at least the below
> minimal use is fine and I cannot see any major disadvantage: if I
> understand the issue, it would fix once and for all the long standing
> troubles with ext/array_allocator/2.cc on various targets.

...however, this would be very nice indeed.

-benjamin