Re: [boost] [fusion] undocumented sequence requirement: convert

Subject: Re: [boost] [fusion] undocumented sequence requirement: convert
From: Joel de Guzman (joel_at_[hidden])
Date: 2012-08-23 10:35:52

On 8/23/2012 7:57 PM, Mathias Gaunard wrote:
> On 23/08/2012 05:39, Joel de Guzman wrote:
>
>> which result_of::convert calls. Here's an example for vector:
>>
>>      struct vector_tag;
>>
>>      namespace extension
>>      {
>>          template <typename T>
>>          struct convert_impl;
>>
>>          template <>
>>          struct convert_impl<vector_tag>
>>          {
>>              template <typename Sequence>
>>              struct apply
>>              {
>>                  typedef typename
>> detail::as_vector<result_of::size<Sequence>::value> gen;
>>                  typedef typename gen::
>>                      template apply<typename
>> result_of::begin<Sequence>::type>::type
>>                  type;
>>
>>                  static type call(Sequence& seq)
>>                  {
>>                      return gen::call(fusion::begin(seq));
>>                  }
>>              };
>>          };
>>      }
>>
>> Pretty much straightforward. I think it is safe to use this extension
>> mechanism. It has been stable for a long time now. Surely, that is
>> not an excuse for it being undocumented though. At any rate, I
>> added this in my TODO list.
>
> Any reason not to make the vector version the default?

No, the result should be the target sequence type identified by
its tag.

Regards,
-- 
Joel de Guzman
http://www.boostpro.com
http://boost-spirit.com