Re: Assertions in principle

From:

Alan Johnson <awjcs@yahoo.com>

Newsgroups:

comp.lang.c++

Date:

Sat, 03 Mar 2007 00:40:01 -0800

Message-ID:

<tIudnb6tw87_qXTYnZ2dnUVZ_oipnZ2d@comcast.com>

Kaz Kylheku wrote:

C. A. R. Hoare (of quicksort fame) wrote this sometime in the early
1970's:

  It is absurd to make elaborate security checks on debugging runs,
  when no trust is putin the results, and then remove them in
  production runs, when an erroneous result could be expensive
  or disastrous. What would we think of a sailing enthusiast who
  wears his life-jacket when training on dry land but takes it
  off as soon as he goes to sea?

So your argument finds good company, indeed.

I'm not sure I like Hoare's analogy. Consider this one: When you are
learning to ride a bicycle you attach training wheels to catch you when
you make a mistake. When you are competing in the Tour de France you no
longer use the training wheels. Analogously, when you are writing code
you use asserts to catch when your invariants stop being invariant.
After you are satisfied the code is correct you disable them for
performance.

That said, I do find the rest of the arguments compelling.

--
Alan Johnson