Re: [boost] [in_place_factory] some suggestions for improvement

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2007-04-04 11:09:25

Tobias Schwinger wrote:
> Andrey Semashev wrote:
>> Hello Tobias,
>>
>> Tuesday, April 3, 2007, 9:02:45 PM, you wrote:
>>
>>> Hi,
>>> in_place_factory can be quite useful, as I found out recently. However,
>>> here are some suggestions to make it event better:
>>> 1. add a construction mechanism for arrays
>>> 2. add a note to the docs about deduction and using boost::ref
>>> 3. have the static 'apply' member function return the pointer to the 
>>> constructed object - just like the placement new operator
>>> 4. use file iteration instead of BOOST_PP_REPEAT for maintainability
>> If I may, I'd like to add:
>>
>> 5. add in_place_factory and typed_in_place_factory for zero
>> constructor arguments. 
> 
> Quick discussion:
> 
> Often the reason against nullary function overloads is the earlier point 
> of instantiation (nullary functions can't be templates), but that 
> shouldn't be the problem here because 'in_place_factory's nested 'apply' 
> is a template and 'typed_in_place_factory' is complete enough to be 
> instantiated. For the 'inline in_place_factory0 in_place()' function the 
> explicit 'inline' keyword is needed, however, not to break the ODR.
> 
> OK. It seems reasonable and it seems there are no unsolvable problems 
> around, so let's add it ;-).
> 
>> I remember someone mentioned this before, but I
>> can't remember any one answered.
> 
> That probably means that there's no maintainer. If that's so, I'd pick 
> up this role.

Well, not really. Seems Fernando Cacciola is still boosting actively 
(I'm CC ing this post to his hotmail address). However, I have 
implemented the proposed code changes (see preliminary patch attached to 
this message) - hoping for Fernando's OK.

Regards,
Tobias