[boost] Re: [serialization] load_construct proposal

From: David Abrahams (dave_at_[hidden])
Date: 2003-10-13 16:24:23

Gregory Colvin <gregory.colvin_at_[hidden]> writes:

> On Monday, Oct 13, 2003, at 12:58 America/Denver, David Abrahams wrote:
>> Robert Ramey <ramey_at_[hidden]> writes:
>>> David Abrahams wrote:
>>>
>>>>> template<class Archive ar, class T>
>>>>> void load(Archive & ar,  T * &t,  unsigned int file_version)
>>>>> {
>>>>>     t = NULL;
>>>>>     try{
>>>>>        t = new T();
>>>>>        ar >> *t;
>>>>>     }
>>>>>     catch(...){
>>>>>         delete t;
>>>
>>>> If you were to do it this way, you should do "t = NULL" here instead,
>>>> but...
> ...
>>> hmm ..  would you buy:
                      ^^^
>>>
>>> template<class Archive ar, class T> // but see below
>>> load(Archive & ar,  T * & t, unsigned int file_version)
>>> {
>>>    t = NULL;
>>>     std::auto_ptr<T> ta(new T());
>>>     ar >> *ta;
>>>     t = ta.release;
>>>  }
>>
>> I'd rather not pay for that one.
>
> Pay for what?  GCC 3.1 produces very similar optimized code for both
> the auto_ptr and explicit catch versions.

I just mean I don't like the out parameter "t".

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com