Re: [boost] Re: Re: [optional]output

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-03-08 17:13:10

Gennadiy Rozental wrote:
> "Peter Dimov" <pdimov_at_[hidden]> wrote in message
> news:00f501c52404$bff4fca0$6501a8c0_at_pdimov...
>> Gennadiy Rozental wrote:
>>> I believe this version is much less intuitive. optional<T> v is
>>> still value of type T which may or may not be present. Accordingly
>>> when we print it we print the value if it present or print nothing
>>> if it not. 
>> 
>> This isn't very useful. The output cannot be read back, and when
>> printing 
> a
>> sequence of optionals much of the information is lost.
> 
> 1. This is not exactly true
> 
> Output most probably will look like:
> 
> a, , v, c, d, ,
> 
> Which should be enough to restore it back

The usual way to read vector<X> _today_ is

    istream_iterator<X> first( is ), last;
    vector<X> v( first, last );

It only works with whitespace as a separator.