Date: Mon, 23 Dec 1996 10:32:02 -0500
Message-Id: <199612231532.KAA18130@delorie.com>
From: DJ Delorie <dj AT delorie DOT com>
To: R DOT L DOT F DOT v DOT Paasen AT stud DOT tue DOT nl
CC: djgpp AT delorie DOT com
In-reply-to: <32B0AC9A.3ABB@stud.tue.nl> (R.L.F.v.Paasen@stud.tue.nl)
Subject: Re: Allegro future


> I agree this time. The speed of compiled C++ code depends on the
> complexity of your class hierarchies. Overloading, lots of virtual
> functions, copy constructors and that sort of things are
> slow-downers.

Copy constructors are the big hits.  Pay careful attention to these!

Virtual functions add only a few cycles per call (two pointer
dereferences and an add, I think), regardless of your class structure.
Function overloading is done at compile time and does not incur a
runtime hit.

> Most C/C++ compilers however allow C and C++ code to be mixed. It
> won't hurt to use C++ code in your C program or vise versa, as long
> as you keep an eye on performance.

For example, I write in C++ most of the time (djgpp is an exception),
but I always use printf instead of cout (for various reasons).

> But hey, if you really want fast code, you should be concerned about
> efficient software design, optimizing algorithms and clever data
> structures.

Two other concerns that C++ addresses is;

1) The code is easier to design and write when you have appropriate
   tools.

2) Cleaner designs result in easier maintenance.

I've also noticed that if you can come up with a cleaner design, you
can often *reduce* the amount of code needed to run it.