unordered containers emplace

[François Dumont]

So here is the new proposition with additional tests experimenting 
emplace insertion using piecewise_construct.

2011-12-08  François Dumont <fdumont@gcc.gnu.org>

         * include/bits/hashtable.h (_Hashtable<>::emplace,
         _Hashtable<>::emplace_hint): Add.
         * include/debug/unordered_set (unordered_set<>::emplace,
         unordered_set<>::emplace_hint, unordered_multiset<>::emplace,
         unordered_multiset<>::emplace_hint): Add.
         * include/debug/unordered_map (unordered_map<>::emplace,
         unordered_map<>::emplace_hint, unordered_multimap<>::emplace,
         unordered_multimap<>::emplace_hint): Add.
         * testsuite/23_containers/unordered_map/modifiers/emplace.cc: New.
         * testsuite/23_containers/unordered_multimap/modifiers/emplace.cc:
         New.
         * testsuite/23_containers/unordered_set/modifiers/emplace.cc: New.
         * testsuite/23_containers/unordered_multiset/modifiers/emplace.cc:
         New.
         * testsuite/util/testsuite_container_traits.h
         (traits_base::has_emplace): Add and defined as std::true_type for
         unordered containers.
         * testsuite/util/exception/safety.h (emplace, emplace_hint): 
Add and
         use them in basic_safety exception test case.
         * doc/xml/manual/status_cxx2011.xml: Update unordered containers
         status.

Tested under linux x86_64 normal and debug mode.

I haven't touch to profile mode for the moment even if I noticed that 
this mode is broken since recent hashtable modifications. I will submit 
an other patch for that.

Ok to commit ?

François


On 12/07/2011 09:43 PM, Paolo Carlini wrote:
> Hi,
>
> On 12/07/2011 09:37 PM, François Dumont wrote:
>> On 12/07/2011 01:01 PM, Paolo Carlini wrote:
>>> Hi,
>>>> Hi
>>>>
>>>>     This is the implementation of emplace and emplace_hint for 
>>>> unordered containers. For the moment in emplace_hint the hint 
>>>> iterator is not considered like in the current insert with hint 
>>>> implementation.
>>> detail: for consistency with _M_insert, I think we should swap the 
>>> arguments of _M_emplace, last true_type / false_type.
>>     This is what I did to begin but it failed to compile, g++ do not 
>> know then when to stop considering arguments as part of the _Args.... 
>> I consider it was a normal limitation of using variadic templates, if 
>> so I can invert parameters of _M_insert to have consistency.
> Of course, sorry. This is absolutely expected, I just didn't consider, 
> formally, that _M_insert is not variadic.
>>>
>>> Much more importantly, I don't think we are doing the right thing 
>>> for map / multimap; honestly I cannot say to have followed in any 
>>> special detail the standardization of the piecewise_construct_t 
>>> things, at the corresponding ISO Meetings, but I think we have to 
>>> involve that pair constructor in this case. I'm adding Jon and Chris 
>>> in CC for you to have more help on this, please also have a look to 
>>> various papers authored by Pablo Halpern et al over the last 2/3 years.
>>     Good point, I hadn't notice this potential issue. I am lucky that 
>> the library is well designed making my patch not so bad. I will add 
>> the necessary tests and resubmit a patch.
> Essentially, I would just recommend adding some tests per Jon's comment.
>
> Thanks!
> Paolo.
>

-------------- next part --------------
A non-text attachment was scrubbed...
Name: unordered_emplace.patch
Type: text/x-patch
Size: 28719 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20111208/79b2fd4c/attachment.bin>