Re: [Boost-users] [fusion] const and transform algorithm

Subject: Re: [Boost-users] [fusion] const and transform algorithm
From: Joel de Guzman (joel_at_[hidden])
Date: 2009-01-07 02:04:17

vicente.botet wrote:

>> I don't know. I'm not sure what you are looking for.
> 
> I just wat to apply the unction get to a tuple of futures and reviver the stored values. 
> T& future<T>::get() is non const

YOu can use a tie (tuple of references).

>>>> vector<int, char> v; v = transform(v, f);
>>> I was lock for in the documentation and I have not found this assignation.
>>> Where in the documentation can I found that I can do that?
>> See the sequence/views concepts and the docs for the containers.
>> For example (http://tinyurl.com/84vdvp):
>>
>> Notation:
>> v Instance of vector
>> s A Forward Sequence
>>
>> Expression Semantics:
>>  v =  s  Assigns to a vector, v, from a Forward Sequence, s.
> 
> Thanks for the reference. I was looking for a function prototype. BTW, the example is not in line with the functions.
> vector<int, float> v(12, 5.5f);
> std::cout << at_c<0>(v) << std::endl;
> std::cout << at_c<1>(v) << std::endl;

Why?

"Semantics of an expression is defined only where it differs from,
or is not defined in Random Access Sequence."

You should read more carefully ;-)

>>> If for_each can change/mutate the sequence itself, why don't have a
>>> mutating_transform that takes a Sequence& and not a Sequence const&
>> Because it is not needed.
>>
>>> Just a last question. How move semantics maps with purely functional
>>> Sequences? Do you plan to add move semantics for the elements of the tuple?
>>> The concept of MovableSequence has a sens for you?
>> Makes sense. Last BoostCon, we had a workshop about implementing
>> Fusion for 0x incuding move. We'll have it when it is available.
> 
> Great! Would you try with a Boost.Move library?

Hah. Wish I had more time :-P

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