RE: [boost] Re: static sized strings

From: Reece Dunn (msclrhd_at_[hidden])
Date: 2004-05-20 11:27:53

John Nagle wrote:
>Reece Dunn wrote:
>>I have uploaded an initial version of this.
>    Thanks. I'll take a look at that shortly.

You might want to take a look at fixed_string.hpp. It is an alternate 
implementation of fixed_string that I intend to replace char_string.hpp once 
it is stable.

Currently, this implementation is missing iterator support (and thus all 
basic_string functionality that relies on begin(), end(), etc). This is 
because I am wondering how to map them from the basic_string adaptor to the 
implementation (knowing that you cannot have const and non-const virtual 
functions).

I have two possible solutions:
[1] name the const versions cXXX (cbegin(), crend(), etc.) -- the problem 
with this is that you have 8 virtual functions!

[2] direct to non-const versions and convert to const iterators:
   inline const_iterator begin() const
   {
      return( const_iterator( const_cast< basic_string_impl & >( *this 
).begin()));
   }
but I am debating whether this is standards compliant and if it is a good 
design decision.

If there are alternate solutions, I'd like to hear them.

Another possibility would be to construct the iterators from offsets:

   inline iterator begin()
   {
      return( get_impl().iter_offset( 0 ));
   }
   inline reverse_iterator rbegin()
   {
      return( reverse_iterator( get_impl().iter_offset( size() - 1 )));
   }

That way you would only need two functions (iter_offset and 
const_iter_offset).

Regards,
Reece

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