Re: [boost] Re: [serialization] load_construct proposal

From: Gregory Colvin (gregory.colvin_at_[hidden])
Date: 2003-10-13 16:52:31

On Monday, Oct 13, 2003, at 15:24 America/Denver, David Abrahams wrote:
> 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".

Aha.  Neither do I.