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Re: this cast to const char*

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Gernot Frisch wrote:

> with "MFC" I can do:
> CString str(_T("test"); printf("%s", str); // prints "test"
> 
> With my own string class, however, there seems to be a 4 byte "header"
> before the string data.
> 
> I have the member >const TCHAR* m_data;< as the first member of my string
> class.
> 
> How does MS doe this?

First, MS could use compiler magic to define the UB of the first line. With 
your own (homegrown) string class, any use of printf would be UB (the specs 
of printf simply won't know about your string class).

Second, I doubt that MS actually does use compiler magic and the first line 
could just "work" by accident. Question: does your string class have a 
virtual method (e.g., the destructor)? does the CString class?


Best,

Kai-Uwe Bux

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Thread

this cast to const char* "Gernot Frisch" <me@privacy.net> - 2011-05-05 19:27 +0200
  Re: this cast to const char* Kai-Uwe Bux <jkherciueh@gmx.net> - 2011-05-05 19:39 +0200
    Re: this cast to const char* "Balog Pal" <pasa@lib.hu> - 2011-05-06 01:11 +0200
      Re: this cast to const char* Marcel Müller <news.5.maazl@spamgourmet.org> - 2011-05-06 01:54 +0200
        Re: this cast to const char* m0shbear <andrey.vul@gmail.com> - 2011-05-05 17:59 -0700
          Re: this cast to const char* James Kanze <james.kanze@gmail.com> - 2011-05-08 07:08 -0700
            Re: this cast to const char* m0shbear <andrey.vul@gmail.com> - 2011-05-08 17:03 -0700
        Re: this cast to const char* "Balog Pal" <pasa@lib.hu> - 2011-05-06 20:15 +0200
        Re: this cast to const char* James Kanze <james.kanze@gmail.com> - 2011-05-08 07:05 -0700
    Re: this cast to const char* James Kanze <james.kanze@gmail.com> - 2011-05-08 07:02 -0700
  Re: this cast to const char* Felix Bytow <felix.bytow@informatik.tu-chemnitz.de> - 2011-05-05 19:40 +0200
    Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-05 10:52 -0700
  Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-05 10:44 -0700
  Re: this cast to const char* gwowen <gwowen@gmail.com> - 2011-05-05 10:50 -0700
    Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-05 10:58 -0700
      Re: this cast to const char* "Bo Persson" <bop@gmb.dk> - 2011-05-05 20:21 +0200
      Re: this cast to const char* gwowen <gwowen@gmail.com> - 2011-05-05 11:27 -0700
        Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-05 11:37 -0700
          Re: this cast to const char* gwowen <gwowen@gmail.com> - 2011-05-05 22:28 -0700
            Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-06 03:55 -0700
              Re: this cast to const char* "Alf P. Steinbach /Usenet" <alf.p.steinbach+usenet@gmail.com> - 2011-05-06 13:25 +0200
                Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-06 06:22 -0700
  Re: this cast to const char* Joshua Maurice <joshuamaurice@gmail.com> - 2011-05-05 22:47 -0700
  Re: this cast to const char* Goran <goran.pusic@gmail.com> - 2011-05-06 06:59 -0700
    Re: this cast to const char* Pete Becker <pete@versatilecoding.com> - 2011-05-06 10:17 -0400
      Re: this cast to const char* James Kanze <james.kanze@gmail.com> - 2011-05-08 07:13 -0700
    Re: this cast to const char* "Gernot Frisch" <me@privacy.net> - 2011-05-09 10:38 +0200
      Re: this cast to const char* Leigh Johnston <leigh@i42.co.uk> - 2011-05-09 13:03 +0100
        Re: this cast to const char* Leigh Johnston <leigh@i42.co.uk> - 2011-05-09 17:51 +0100
      Re: this cast to const char* Öö Tiib <ootiib@hot.ee> - 2011-05-09 09:40 -0700

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