Re: [Boost-users] [fusion] nth runtime element of a sequence

Subject: Re: [Boost-users] [fusion] nth runtime element of a sequence
From: MM (finjulhich_at_[hidden])
Date: 2014-02-24 12:55:37

On 24 February 2014 14:28, Larry Evans <cppljevans_at_[hidden]> wrote:

> On 02/24/14 05:04, Krzysztof Czainski wrote:
>
>> 2014-02-24 11:55 GMT+01:00 MM <finjulhich_at_[hidden]
>> <mailto:finjulhich_at_[hidden]>>:
>>
>>
>>     Hello,
>>
>>     I just wanted to confirm there's no provided method to get the n'th
>>     element of say a fusion vector where n is known at runtime, except
>>     of handling it explicitkly with a switch case?
>>
>>     Thanks
>>
>>     MM
>>
>>
>> If such a function existed, what return type would it have?
>>
>> Regards,
>> Kris
>>
>>  What about:
>   variant<T1,T2,T3> get(unsigned n, vector<T1,T2,T3>)
> ?  For example:
>
>   vector<T1,T2,T3> vec(T1(),T2(),T3());
>   variant<T1,T2,T3> var;
>   var = get(2,vec);
>   assert(var.which(),2);
>
> -regards,
> Larry
>
> Possible, a variant over the unique types in the sequence.
What would the impl look like though?

MM