Re: [boost] Boost super_string

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2006-10-12 15:49:48

"Jeff Garland" <jeff_at_[hidden]> wrote

> Caleb Epstein wrote:
>> On 10/12/06, Arkadiy Vertleyb <vertleyb_at_[hidden]> wrote:
>>> "Jeff Garland" <jeff_at_[hidden]> wrote
>>
>>>> So a core goal of the library is that you can
>>>> use super_string in some code and then seamlessly pass that instance to
>>>> existing interfaces written in terms of std::string for zero cost.
>>> Not exactly...  the cost would be runtime -- to allocate a copy of the
>>> string.  You wouldn't be able to pass anything other than "std::string" 
>>> to
>>> "const std::string&" without copying it first, would you?
>>
>> Anything derived from std::basic_string<char> would work too.  Super 
>> String is:
>>
>>    template<class char_type >
>>    class basic_super_string : public std::basic_string<char_type>
>>
>> So there would be no copies.
>
> Exactly right.

I didn't realise that it's derived from the standard string, sorry.

However, this will bring other problems.  First, traits designed for 
std::string will not work for this new class.  More importantly, according 
to the standard, the basic_string class destructor is not virtual, and so 
basic_string is not intended for derivation.  As far as I can remember, 
deriving from a standard container has always been considered a bad 
practice...

Regards,
Arkadiy