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Re: Default implementation of std::hash template
On 06.03.2013, at 21:04, Jonathan Wakely wrote:
> On 6 March 2013 19:13, Daniel Frey wrote:
>>
>> we can have both is_hashable and the static_assert, which fires if someone tries to instantiate the template:
>>
>> std::unordered_set< std::pair< int, int > > dummy; // fires the static_assert.
>>
>> What do you think?
>
> On the trunk we just have an undefined primary template, there's no
> static_assertion, and your trait works with GCC 4.8 (after adding the
> missing closing parenthesis for the sizeof)
Oh, that's good news! :)
One question, if you allow: Was there some DR against the standard and is it now guaranteed that the primary template is undefined? Because previously the standard was only speaking about the specializations and there seemed to be no requirements for the primary template whatsoever. And from what I've heard VC++ also has (had?) a static_assert in place...
Best regards, Daniel