You might want to distinguish that promulgation between active languages and
archived ones. Much fewer languages are leading-edge.
The programming world occupies a spectrum from embedded to distributed. From
bits inside registers in specific hardware, to active content like web pages
that can run in any generic device.
C++ is efficient, modular (roughly), typesafe (roughly), and more flexible &
maintainable than assembler. It is also statically-typed, and purely
compiled.
Use C++ from the embedded level to the OS level to large, performance bound
systems.
Use a higher level language to drive C++.
For example, oggle my Flea:
http://flea.sourceforge.net/balancingAct.png
That program drives OpenGL with several layers of stuff. At the lowest
layer, the microcode in the graphics chipset in my graphics card, C++ could
easily have been used to blast all the bits around in an image. C++ competes
directly with Assembly and Machine Language because programs that are easy
to read and change can be faster than programs that force you to think of
the path of each bit.
But maybe the microcode in my graphics chipset wasn't C++; the miracle of
encapsulation and drivers means I don't know if that layer is C++.
At the next layer up, the OS drivers, including OpenGL, could have been
written in C++, and again they might not have been. The odds are very high
they were written in a C language, such as Standard C or GNU C.
Next, the frame around my OpenGL is written in Qt, which is an exquisite and
elegant framework written in pristing C++...
...with one exception. Because C++ uses statically typed polymorphism
(polymorphism that requires inheritance), and because GUIs work best with
the Observer Pattern written in a dynamically typed language (a
message-based language like Smalltalk), Trolltech invented two new C++
keywords, signals and slots, and added them to your compiler.
The moral is the farther you are from the hardware, the more dynamism you
need.
In the left panel of my user interface is a snip of Ruby code, which is a
very high-level language that competes with Perl and Smalltalk - but
certainly not Assembler. My Ruby code drives the commands that generate the
graphical primitive commands sent into OpenGL. So the Ruby code generates
the shape you see, and the OpenGL code renders it.
This far from the metal, the efficiency of static typing is less important
than the flexibility of dynamic typing. So when my system uses Ruby to
generate a shape, you don't need to recompile everything just to change the
shape.
Similarily, if you write a database engine in C++, you drive it with SQL, a
soft dynamic (and declarative) language.
All modules in a program must perform a balancing act between too much
typechecking and too little. Use C++ when those benefits are obvious.
