Re: [boost] [serialization] use of unsigned int instead of size_type

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-02-11 16:58:35

David Abrahams wrote:
> "Peter Dimov" <pdimov_at_[hidden]> writes:
>
>> David Abrahams wrote:
>>> "Robert Ramey" <ramey_at_[hidden]> writes:
>>>
>>>> I was expecting to see your enhancements for arrays to get
>>>> included and for collection_size (or whatever)  to be part of this.
>>>> I'm not sure what status of this is and/or if it conflicts with the
>>>> recent feature
>>>> freeze.
>>>
>>> IMO the size_type change should be considered a bugfix, as it was
>>> not possible to portably serialize collections without it.
>>
>> The change is not trivial. Using a size_t typedef means that program
>> A can write an unsigned int and program B can read an unsigned long.
>> This will appear to work at first because the serialization library
>> doesn't include archives where this is significant. Yet.
>
> I don't know exactly how to interpret your remarks.  It sounds like
> you're describing the status quo here, which would seem to argue that
> the change is necessary.

The status quo is that the size of the container is consistently written or 
read as an unsigned int, is it not?

Consider the simplistic example:

void f( unsigned int ); // #1
void f( unsigned long ); // #2

void g( std::vector<int> & v )
{
    unsigned int n1 = v.size();
    f( n1 ); // #1

    size_t n2 = v.size();
    f( n2 ); // ???
}