question I really want to discuss.
I was just pondering the competing applicability of C vs. C++ in certain
problem domains. Then I saw this as Stroustrup's FAQ of the day:
http://www.research.att.com/~bs/bs_faq.html#C-is-better
Q:"C is better than C++ for small projects, right?"
A:"Not in my opinion. I never saw a project for which C was better than C++
for any reason but the lack of a good C++ compiler."
What I was thinking about was not the size of the project, but rather the
level of the project in terms of abstraction. Here are some products I
know of which are written in C, and I wonder if there is any compelling
reason that C++ could not be used, or any significant advantage to using
C++.
DBus, OpenSSH, the Linux kernel, OpenGL, Emacs (first implemented in C by
James Gosling).
If I were asked what the biggest problem with using C++ for a project is, I
would say the difficulty in learning C++. Linus Torvalds has used some
strong words to state his opinion on using C++ in the Kernel.
<quote>
On Tue, 20 Jan 2004, Robin Rosenberg wrote:
This is the "We've always used COBOL^H^H^H^H" argument.
In fact, in Linux we did try C++ once already, back in 1992.
It sucks. Trust me - writing kernel code in C++ is a BLOODY STUPID IDEA.
The fact is, C++ compilers are not trustworthy. They were even worse in
1992, but some fundamental facts haven't changed:
- the whole C++ exception handling thing is fundamentally broken. It's
_especially_ broken for kernels.
- any compiler or language that likes to hide things like memory
allocations behind your back just isn't a good choice for a kernel.
- you can write object-oriented code (useful for filesystems etc) in C,
_without_ the crap that is C++.
In general, I'd say that anybody who designs his kernel modules for C++ is
either
(a) looking for problems
(b) a C++ bigot that can't see what he is writing is really just C anyway
(c) was given an assignment in CS class to do so.
Feel free to make up (d).
Linus
</quote>
OTOH, we have this more scientific sounding assessment suggesting there /is/
merit to using C++ in the kernel:
http://netlab.ru.is/exception/LinuxCXX.shtml
My own opinion is that I think C code is ugly. That really is a bit more
reasoned than it may sound. A good example is OpenGL and its hundreds of
flags used as parameters to functions all in one flat namespace. I will
however, concede that C++ programmers often fail to make effective use of
namespaces, especially when communicating with humans. I am at fault in
the area.
A good example of what I mean here is the common practice of talking about
"global" functions in the std namespace. There are many times when text,
or code could be made more clear by being explicit about, e.g., which
getline is being described or invoked. IOW, rather than writing getline in
a tutorial, or other context where the meaning may not be clear it may be
more effective to write std::getline. I sometimes get the sense that C++
programmers feel mildly embarrassed about namespaces. Many also fail to
see namespaces as a means of human-to-human communication. They think of
them exclusively as a means of avoiding naming collisions.
I do wonder if the abstractness of C++ does (or can) make C++ more difficult
to work with when it comes to code that's close to the metal. That is,
code which depends closely on the exact memory addresses being accessed,
and order of machine instruction invocation?
Is C++ a good language for writing device drivers and other OS components?
--
If our hypothesis is about anything and not about some one or more
particular things, then our deductions constitute mathematics. Thus
mathematics may be defined as the subject in which we never know what we
are talking about, nor whether what we are saying is true.-Bertrand Russell
