Re: [boost] Re: Formal review of "OutputFormatters"library beginstoday

From: John Torjo (john.lists_at_[hidden])
Date: 2004-09-13 14:22:20

> 
> 
> This might be easier if instead of formatter holding DelimeterType 
> objects for each delimeter, have it store an io::delimeter< CharT > 
> object and have that responsible for access, thus:
> 
>   template< typename CharT >
>   class delimeter
>   {
>      private:
>         const CharT * value;
>         bool is_set;
>      public:
>         const CharT * get() const{ return( is_set ? value : 
> ios_base::pword -> value()); }
>         void set( const CharT * v ){ value = v; is_set = true; }
>         delimeter(): value( "" ), is_set( false ){}
>   };
> 
> and
> 
>   template< typename CharT >
>   class formatter
>   {
>      public:
>         delimeter< CharT > separator; // separator is now a property!
>   };

that's what I was actually aiming at ;)

> 
>>> The main questions are:
>>> [1] how do you store different DelimeterTypes in this mechanism?
>>
>>
>> Which brings us to ;) :
>> I think one type of delimeter is enough (I assume you wholeheartidly 
>> disagree with this).
> 
> 
> I don't wholeheartedly disagree... I am open to persuasion ;)
> 
>> This type should be the std::basic_string<underlying_char_type>().
> 
> 
> This would still mean that you have one per underlying_char_type, so the 
> same problem exists although it is now in a smaller problem domain. My 

Nope, in this case, the problem does not exist.
It's because you have this correspondence:
1 stream - 1 underslying character type - 1 object that can keep delimeters

As oposed to:
1 stream - N delimeter_types - N objects keeping these delimeters.

> main reason against using std::basic_string as the storage type is 
> performance (excessive copying of the delimeter values). Also, what 
> about managed strings in C++/CLI? Don't they require a String^ type, or 
> am I missing something?

whoa. I have no idea. But I do think that std::string should work ;) Or 
am I dreaming ;) ?

Best,
John

-- 
John Torjo
-- john_at_[hidden]
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