On Wed, 8 Aug 2012, François Dumont wrote:
On 08/08/2012 03:39 PM, Paolo Carlini wrote:
On 08/08/2012 03:15 PM, François Dumont wrote:
I have also introduce a special std::pair constructor for container usage
so that we do not have to include the whole tuple stuff just for
associative container implementations.
To be clear: sorry, this is not an option.
Paolo.
Then I can only imagine the attached patch which require to include tuple
when including unordered_map or unordered_set. The
std::pair(piecewise_construct_t, tuple<>, tuple<>) is the only constructor
that allow to build a pair using the default constructor for the second
member.
I agree that the extra constructor would be convenient (I probably would
have gone with pair(T&&,__default_construct_t), the symmetric version, and
enough extra constructors to resolve all ambiguities). Maybe LWG would
consider doing something.
+ __p = __h->_M_allocate_node(std::piecewise_construct,
+ std::make_tuple(__k),
+ std::make_tuple());
Don't you want cref(__k)? It might save a move at some point.
--
Marc Glisse
