libc++: implement uses-allocator construction

[Howard Hinnant]

On Sep 10, 2013, at 11:19 AM, Marshall Clow <mclow.lists at gmail.com> wrote:

> Split out from <dynarray>.
> Section 20.8.7.2 (at least in N3691)
> 
> Howard wrote:
> 
>> However when I just now tried to do so, I created circular header dependencies.  After investigating further, adding <new> to <__functional_base> isn't so bad.  Everything <new> includes is already included by <__functional_base>.  So <__functional_base> only swells by the immediate contents of <new> which is pretty small.
>> 
>> In summary, my suggestion is:
>> 
>> *  Add #include <new> to <__functional_base>
>> 
>> *  Move allocator_arg_t, __uses_alloc_ctor, __user_alloc_construct to <__functional_base>.
> 
> and then:
> 
>> __user_alloc_construct and __user_alloc_construct_impl needs decoration with inline _LIBCPP_INLINE_VISIBILITY.
>> 
>> Case 0 of __user_alloc_construct_impl, remove unused argument name "__a".
> 
> Did all that :-)
> 
> -- Marshall
> 
> Marshall Clow     Idio Software   <mailto:mclow.lists at gmail.com>
> 
> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait).
>        -- Yu Suzuki
> 
> <uses-alloc.patch>

Very nice job on a very low level refactoring.  I can't find anything to complain about.

Please commit, and thanks!

Howard