Re: Book recommendations: Generic programming
on Tue Mar 20 2007, "Rune Allnor" <allnor-AT-tele.ntnu.no> wrote:
On 19 Mar, 20:20, David Abrahams <d...@boost-consulting.com> wrote:
on Mon Mar 19 2007, "Rune Allnor" <allnor-AT-tele.ntnu.no> wrote:
To me, contemporary C++ is an all but completely new
language, compared to the language I left in -97.
I think you're seeing the shift away from focusing on low-level
language features and toward the use of high-level libraries. I agree
that's a profound change, and there should be more books that focus on
how to be effective with libraries.
I certainly see that *something* has changed, I don't know
exactly what, though.
Most people who use C++ use the language for one single reason:
The run-time performance of compiled code. Other languages are
require less programming time, if mediocre or poor run-time
is acceptable.
Yep. The STL brought us the reality that it's possible to raise the
level of abstraction without loss of efficiency.
People here might not agree, but most people
who aren't comfortable with C++ because they think it "too
complicated", "too difficult" or "too specialized" in some
weird way.
.....sure...
I had a hard argument with a guy here a few months ago (in
a different newsgroup, but still) over the STL. Back in the
-90s I reduced the run-time of my C++ program from some 14
minutes to 40 seconds by inlining certain operations in
a class for complex numbers I had written myself.
This is exactly the sort of thing that matters to a hobby
C++ programmer like myself: Get the run-time down. That's
one of two reasons why I use C++ and not matlab; the other
is code maintenance for complex programs. I intepreted
the STL as introducing run-time overhead in my programs,
due to the fact that it introduces an intermediate layer
in the code.
Only a couple of days a go did I find a text where a key
property of the STL was spelled out: Template libraries
require substantia parts of the code to be visible to the
compiler at all times, so these libraries are implemented
as mere header files, and can easily be optimized and
inlined by the compiler.
Well, that's a small but significant part of it. The other major part
is the preservation of type information which, in an OO-style program,
would be lost at the inner layer. Having the type information inside
the abstractions means that you can directly invoke the
implementations of generic operations that are most appropriate to the
concrete types involved.
--
Dave Abrahams
Boost Consulting
www.boost-consulting.com
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