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

[Robert J. Hansen]

> How come you dont have a single kernel in C++ ?

At one time, my Linux kernel was compiled with g++.  So yes, you do have
kernels written in C++.

I've written device drivers in C++, and those are kernelspace.

One of the big problems with C++ are the fragile base classes.  Any
change to the declaration of a base class requires rebuilding every
class which inherits from it.  As a result, it's generally not a good
idea to represent a kernel as a collection of classes; any change to the
kernel would require you to not only rebuild your kernel, but also
rebuild a lot of your userspace apps.

Another problem is the complex memory management required for
templates.  You rarely mess around with memory yourself when writing STL
code, but STL does a lot of strange memory management
behind-the-scenes.  This gets you into a chicken-and-egg problem when
you're trying to write a kernel memory manager.

As a result, very few people use either templates or objects for kernel
programming.  And once you do away with templates and objects, you might
as well be programming in C.