Re: Memory and error management approaches

Newsgroups	comp.lang.c
Date	2015-11-07 02:23 -0800
References	(9 earlier) <fg0qgc-mgq.ln1@wilbur.25thandClement.com> <n1dnm8$k1u$1@dont-email.me> <8737wjk1lw.fsf@gmail.com> <macvgc-dta.ln1@wilbur.25thandClement.com> <slrnn3q4t2.5q5.grahn+nntp@frailea.sa.invalid>
Message-ID	<0a52aa48-e09d-4f70-82fd-7d5024ef5ba8@googlegroups.com> (permalink)
Subject	Re: Memory and error management approaches
From	Malcolm McLean <malcolm.mclean5@btinternet.com>

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On Friday, November 6, 2015 at 8:55:08 PM UTC, Jorgen Grahn wrote:
>
> But that's something I feel because of my C++ experience; I have never
> seen a good definition of RAII (which doesn't mean there isn't one).
> 
It's not that it can't be defined.

Resource allocation occurs only in constructors, which are only called 
when named variables are initialised.

It's that it's desperately hard to actually keep to the idea.
You're loading a text from disk. OK, fine, you can write a constructor
that loads the file. You then want to go through each line. OK,
we can define a string called line, and initialise it with
string line = text.readline(i);

Now we want to add "by Fred" to the end of the text.
But we cant do that. We can't write a routine that allows us to
append a line to the text, because that would involve acquiring a 
resource (if only space for an extra char *), and we can only do
that in constructors that are triggered when a names object comes
into scope.
What we can do is

Text book = loadtextfile("Fred's book");
Text signedbook = book.appendline("by Fred");

But I don't think anyone actually programs like that. It gets even harder
when you want to add a list of lines in response, say, to user input.

Thread

Memory and error management approaches "Morten W. Petersen" <morphex@gmail.com> - 2015-11-02 10:17 +0100
  Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-02 22:25 +1300
    Re: Memory and error management approaches "Morten W. Petersen" <morphex@gmail.com> - 2015-11-02 10:36 +0100
      Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-02 22:41 +1300
        Re: Memory and error management approaches "Morten W. Petersen" <morphex@gmail.com> - 2015-11-02 11:05 +0100
          Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-02 12:15 +0000
            Re: Memory and error management approaches "Morten W. Petersen" <morphex@gmail.com> - 2015-11-02 20:31 +0100
          Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-03 09:48 +1300
            Re: Memory and error management approaches supercat@casperkitty.com - 2015-11-02 13:17 -0800
              Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-03 10:29 +1300
                Re: Memory and error management approaches supercat@casperkitty.com - 2015-11-02 13:48 -0800
            Re: Memory and error management approaches "Morten W. Petersen" <morphex@gmail.com> - 2015-11-02 22:31 +0100
              Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-03 11:02 +1300
                Re: Memory and error management approaches supercat@casperkitty.com - 2015-11-02 15:21 -0800
              Re: Memory and error management approaches <william@wilbur.25thandClement.com> - 2015-11-03 17:24 -0800
                Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-04 14:38 +1300
                Re: Memory and error management approaches <william@wilbur.25thandClement.com> - 2015-11-04 10:48 -0800
                Re: Memory and error management approaches supercat@casperkitty.com - 2015-11-04 11:28 -0800
                Re: Memory and error management approaches James Kuyper <jameskuyper@verizon.net> - 2015-11-04 14:54 -0500
                Re: Memory and error management approaches Gareth Owen <gwowen@gmail.com> - 2015-11-06 07:50 +0000
                Re: Memory and error management approaches <william@wilbur.25thandClement.com> - 2015-11-06 11:40 -0800
                Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-07 09:38 +1300
                Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-06 20:55 +0000
                Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-07 02:23 -0800
                Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-07 11:29 +0000
                Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-07 04:18 -0800
                Re: Memory and error management approaches asetofsymbols@gmail.com - 2015-11-07 05:41 -0800
                Re: Memory and error management approaches asetofsymbols@gmail.com - 2015-11-07 06:27 -0800
                Re: Memory and error management approaches Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2015-11-07 18:20 +0100
                Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-07 10:28 -0800
                Re: Memory and error management approaches gazelle@shell.xmission.com (Kenny McCormack) - 2015-11-07 19:01 +0000
                Re: Memory and error management approaches raltbos@xs4all.nl (Richard Bos) - 2015-11-10 16:14 +0000
                Re: Memory and error management approaches Gareth Owen <gwowen@gmail.com> - 2015-11-10 21:13 +0000
                Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-10 19:26 +0000
                Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-03 18:25 -0800
                Re: Memory and error management approaches "Morten W. Petersen" <morphex@gmail.com> - 2015-11-06 10:05 +0100
    Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 02:15 -0800
      Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-02 12:01 +0000
        Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 06:05 -0800
          Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-02 17:18 +0000
            Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 09:27 -0800
              Re: Memory and error management approaches Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-02 23:02 +0000
              Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-03 12:07 +1300
                Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 15:23 -0800
            Re: Memory and error management approaches supercat@casperkitty.com - 2015-11-02 10:28 -0800
      Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-03 09:34 +1300
        Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 14:05 -0800
          Re: Memory and error management approaches Ian Collins <ian-news@hotmail.com> - 2015-11-03 11:27 +1300
            Re: Memory and error management approaches Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-03 18:15 -0800

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