Re: [boost] boost::factory?

From: David Abrahams (dave_at_[hidden])
Date: 2007-07-01 21:13:34

on Tue Jun 19 2007, Tobias Schwinger <tschwinger-AT-isonews2.com> wrote:

> David Abrahams wrote:
>> on Sun Jun 17 2007, Tobias Schwinger <tschwinger-AT-isonews2.com> wrote:
>>> Interface draft:
>>> ================
>>>
>>>      factory<T>     // constructs X and returns it by value
>>>      factory<T*>    // uses operator new, returns a pointer
>> 
>> auto_ptr, please.
>
> Generic algorithms won't 'get' it.

You have generic algorithms that expect to get ownership of a
dynamically-allocated pointer?

> In this light, it seems better to have a separate template for pointers, 
> so you clients can specify what they want, explicitly:
>
>      new_< T* >
>      new_< auto_ptr<T> >
>      new_< special_smartie<T> >
>
> (Seems tricky to deduce T but it might be doable).

  boost::pointee<X>::type

>>> Where operator() takes a variable number of arguments, forwarded to the
>>> constructor.
>> 
>> 
>> Isn't in-place construction the most general case?
>
> It sure is, but not necessarily the most handy. How to tell e.g. 
> std::transform to allocate memory for the transformed elements?
>
> Not sure I really got your point, here.

Just that you might want to support the general case and build the
others on top... if possible.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com
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