From -6128804679395583897 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,2dadf1d1c3a45d35 X-Google-Attributes: gidf78e5,public From: James Kanze Subject: Re: Why basic_string != vector ? Date: 1997/03/13 Message-ID: #1/1 X-Deja-AN: 225210051 References: <3325F838.6AEF@pratique.fr> X-Original-Date: 13 Mar 1997 11:07:16 +0100 Organization: - X-Auth: PGPMoose V1.1 PGP comp.std.c++ Newsgroups: comp.std.c++ Originator: fjh@murlibobo.cs.mu.OZ.AU Valentin Bonnard writes: |> The question is in the subject line: why basic_string != vector ? |> |> basic_string provide de same basic services as vector; it just |> add: |> - conversion from 0 terminated string |> - conversion to 0 terminated string (data/c_str) |> - concatenation (+ and +=) with basic_string and string element |> - operator = with 0 terminated string and string element |> |> Basically this is: |> (1) conversions with 0 terminated arrays |> (2) one element work as an array |> (3) concatenation |> |> While (3) may also make sens for vector, (1) or (2) don't |> often. |> |> So my question really is: why are they independent concepts ? |> (even if they aren't equivalent abstractions) There are probably a number of reasons. One of the most important is certainly the fact that it is instantiated on a "traits" class; you can have several basic_string's implemented over char with different multi-byte encodings (or even different single byte encodings, e.g. ISO 8859-x), for example. Each has a different type, and cannot (easily) be mixed. Note that the support for multibyte encoding is significant; the actual value of an element (character) in a string cannot be determined uniquely by looking at that element alone; it also depends on the current mbstate. -- James Kanze home: kanze@gabi-soft.fr +33 (0)1 39 55 85 62 office: kanze@vx.cit.alcatel.fr +33 (0)1 69 63 14 54 GABI Software, Sarl., 22 rue Jacques-Lemercier, F-78000 Versailles France -- Conseils en informatique industrielle -- --- [ comp.std.c++ is moderated. To submit articles: try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ FAQ: http://reality.sgi.com/employees/austern_mti/std-c++/faq.html ] [ Policy: http://reality.sgi.com/employees/austern_mti/std-c++/policy.html ] [ Comments? mailto:std-c++-request@ncar.ucar.edu ]