[boost] Re: Possible boost addition: sub string and const s tring.

From: Vincent Finn (vincent_finn_at_[hidden])
Date: 2002-11-21 06:07:04

Alexei Novakov wrote:
> "Vincent Finn" <vincent_finn_at_[hidden]> wrote in message
> news:3DDB6C2E.9090809_at_agilent.com...
> 
>>Forwarded to main Boost list - that's the more appropriate venue for
>>discussions of possible additions.
>>
>>-- Jim Hyslop boost-users moderator.
>>
>> > -----Original Message-----
>> > From: alexei_novakov [mailto:alexei_novakov_at_[hidden]]
>> > Sent: Monday, November 18, 2002 7:05 PM
>> > To: Boost-Users_at_[hidden]
>> > Subject: [Boost-Users] Possible boost addition: sub string and const
>> > string.
>> >
>> >
>> > Hello everyone.
>> >
>> > I have two classes which I found pretty handy: sub_string (behaves as
>> > a mirror of the portion of master basic_string) and const_string (C-
>> > string wrapper). Nice thing about these two is they implemented as
>> > template specialization of basic_string which has advantages:
>> > a) familiar interface;
>> > b) possibility to reuse the code written for basic_string (like
>> > string streams, lexical casts, etc).
>> >
>> > Any interest?
>> >
>> > Regards.
>> >
>> > Alexei Novakov
>>
>>Sounds interesting, like slice on a valarray
>>
>>When I have to do a lot of manipulation of sub string and can't afford
>>to copy back and forward I normally resort to using vector<char>; this
>>sounds a lot handier
>>
>>How does it work ?
>>
>>Vin
>>
> 
> 
> The idea is simple. Sub string is declared as basic_string template
> specialization:
> 
> template <typename CHAR, typename TRAITS, typename ALLOCATOR>
> class basic_string<CHAR, TRAITS, basic_string<CHAR, TRAITS, ALLOCATOR> >
> 
> The interfase is the same as for basic_string (except constructors). Sub
> string instances contain reference to master string and boundaries (start
> and size). One can use it like this:
> 
> // Start
> typedef basic_string<string::value_type, string::traits_type, string>
> sub_string;
> 
> string str("1234567890");
> sub_string ss(str, 2, 5); // master string, start position, size
> 
> assert(lexical_cast<int>(ss) == 34567);
> 
> ss = "$$";
> 
> assert(str == "12$$890");
> // End
> 
> All the basic_string operators (like +, ==, !=, <, >, <=, >=) are overloaded
> to be used for both strings and sub strings.
> 
> Similar approach is used for const_string (C string wrapper), but only const
> methods of basic_string are implemented.
> 
> Alexei.

Cool, I'd definitely use it
Seeing as there is a move to submit a library of string helpers at the 
moment it might be worth submitting this at the same time!

        Vin