Re: [boost] Is there any interest in tagged tuple?

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2005-06-27 07:10:13

Pavel Chikulaev wrote:
> Hi all,
> 
> Is there any interest in tagged tuple as extension of tuples library or fusion 
> library?
> The example:
> 
> struct name_t {}; //tagged types
> struct year_t {};
> 
> void foo()
> {
>      tagged_tuple<std::string, name_t, int, year_t> s;
> 
>      s.get<name_t>() = "Hello World"!;
>      s.get<year_t>()   = 2005;
>      assert(s.get<0>() == s.get<name_t>());
>      assert(s.get<1>() == s.get<year_t>());
> }
> 
> It already works in VC7.1 and VC8.0 :)
>

Reminds me of the mpl::inherit_linearly example:

     http://www.boost.org/libs/mpl/doc/refmanual/inherit-linearly.html

(it shows a few-lines tuples implementation, using the value type as an "index").

> What do you think?

As far as I can see, the semantics you propose can be decorated easily via MPL 
(set,begin,find,distance) and their use is uncommon enough to leave it an 
excercise to the user. Am I missing something ?

Regards,

Tobias