[prog] School problem, C++ and cout.precision(2);

[Ganesh Swami]

hello,

Robert J. Hansen wanted us to know:

> As a word of warning: I'm a certified language zealot.  My two preferred
> languages are LISP and C++; C++ for when I need fine-grained control
> over hardware and LISP for everything else.  I've been a C++ programmer
> for thirteen years now.

Goody ! Thirteen years back, I still had the thumb in my mouth ;-)

> > How many people use C++ completely ? Actually very few. Is it worth
> > learning Templates and other advanced C++ features ?
> 
> Absolutely.  No templates = no STL.  No STL = you're not using the best
> feature, IMO, of C++.
> 
> > I consider Qt/KDE to be a very good C++ library. It uses exactly what is
> > required. No more bloat. But still they cant beat the overheads.
> 
> The `overhead' of C++ is largely a myth.  There's a hard and fast rule
> in the C++ community: You Don't Pay For What You Don't Use.  If you
> don't use templates, you don't suffer the runtime penalty for them; if
> you don't use vfuncs, you don't suffer the runtime penalty for them;
> etc.  YDPFWYDU--which is pretty much C++'s answer to Perl's TMTOWTDI--is

Absolutely. A C program thru a C and a C++ compiler should yield similar
results.

> sometimes ignored by compiler authors.  For instance, Sun's compiler was
> for years infamously bad with templates; the most trivial use of
> templates could bloat code size by over a meg.

Hmm...How do Microsoft's compiler fare ? Do they add their /custom/
extensions ?

> On the other hand, though, GCC 3.2 is acceptably good.  The /linker/ is
> still horrible, but the compiler is pretty good.  Under glibc, C++
> programs often have unacceptable startup times because of some pretty
> poor linker behavior.  The GCC crew is trying to address this issue.

So, is GLIBC the library that implements C functions like *printf() ? I
find KDE to be real fast under FreeBSD. Is it because FreeBSD does not
use GLIBC ?

> 
> > I believe C++ comes with its own classes for implementing stacks, hashes
> > and other data structures. Does anybody use them ?
> 
> All the time.  Using them has probably doubled my productivity and
> halved my bugs.  No, I'm not kidding.

Maybe thats why we have some die hard fans for Delphi. It provides units
for everything.

> > I personally do not like streams. Its more trouble than ease. And, I
> > love strongly typed languages (you can call PHP an exception ;-))
> 
> C++ is a strongly typed language, which is why in the archives I was
> surprised to see you using C-style (typeless) casts.  C++ provides
> typesafe casts.

I have been largely ignorant of C++. Time to play 'catchup'.

Do you still deal with complex pointer arithematic ? I dont mean simple
stuff by pass-by-ref, but like using arrays and lists. I thought people
jumped to Java, because it was more difficult to make pointer mistakes.
But, I dont know Java too....so I may be wrong.

> As a short example of some C++ which makes full use of templates and the
> STL...
> =====
<snip code I dont understand>
> =====
> 

This is greek to me.

> As another example, Codebook--a GnuPG GUI that I'm working on--uses
> templates, objects and virtual function calls extensively.  All three of
> them are usually considered to be bloatware.  But Codebook manages to
> come in at under 180k, which isn't bad at all for an app.

So which GUI framework are you using ?

	-- Ganesh
-- 
:       _ /~\'_
         (o o)
=====oooO==U==Oooo================[Ganesh Swami]==========
Well, to be Frank, I'd have to change my name.