[v3 PATCH] Protect allocator-overloads of tuple-from-tuple constructors from cases that would create dangling references.

[Paolo Carlini]

Hi Ville,

On 29/05/2016 16:42, Ville Voutilainen wrote:
> On 28 May 2016 at 21:25, Ville Voutilainen <ville.voutilainen@gmail.com> wrote:
>> The fix to avoid binding dangling references to temporaries for tuple's
>> constructors that take tuples of different type didn't include the fix
>> for allocator overloads. That was just lazy, and I should feel ashamed.
>> This patch fixes it, and takes us one step further to pass libc++'s testsuite
>> for tuple. The added _NonNestedTuple checks could actually be folded
>> into the recently-added _TMCT alias, but I'll do that as a separate cleanup
>> patch. For now, this should do as an easy and straightforward fix.
>>
>> Tested on Linux-x64.
>>
>> 2016-05-28  Ville Voutilainen  <ville.voutilainen@gmail.com>
>>
>>      Protect allocator-overloads of tuple-from-tuple constructors
>>      from cases that would create dangling references.
>>      * include/std/tuple (tuple(allocator_arg_t, const _Alloc&,
>>       const tuple<_UElements...>&), tuple(allocator_arg_t, const _Alloc&,
>>       tuple<_UElements...>&&)): Add a check for _NonNestedTuple.
>>      * testsuite/20_util/tuple/cons/nested_tuple_construct.cc: Adjust.
> Since Jonathan is going to be out-of-reach for next week due to a
> well-deserved holiday, would it be ok if Paolo approves such patches?
Admittedly, I didn't follow in detail all your latest contributions, but 
sure, if this work goes only in trunk, please go ahead at your ease. We 
can certainly revisit details when Jon comes back, but trunk is 
currently in Stage 1, open for any kind of development work...

Thanks,
Paolo.