Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!usc!polyslo!ttwang
From: ttwang@polyslo.CalPoly.EDU (Thomas Wang)
Newsgroups: comp.lang.c++
Subject: Re: Handling trouble in C++
Keywords: exception error
Message-ID: <13767@polyslo.CalPoly.EDU>
Date: 24 Aug 89 22:08:16 GMT
References: <13262@well.UUCP>
Reply-To: ttwang@polyslo.CalPoly.EDU (Thomas Wang)
Distribution: usa
Organization: Cal Poly State University -- San Luis Obispo
Lines: 23

In article <13262@well.UUCP> nagle@well.UUCP (John Nagle) writes:

>In C++, unlike C, a considerable fraction of the execution can
>take place implicitly, within constructors and destructors, rather
>than in explicitly called functions.  But there is no way for a
>constructor or a destructor to signal an error condition to the
>invoker.

You have hit a major problem of C++, that it does not have an exception
handling mechanism.  The programmer has to handle errors in an ad-hoc
manner.  error checking in normal functions are tedious enough.  And
error checking in constructor and destructor are particularly nasty.

You can have a variable in a class that tells if its state is in a good
state.  But this will cause the deferred handling of errors and an increase
in complexity.

>                                       John Nagle

 -Thomas Wang ("I am, therefore I am."
                 - Akira               )

                                                     ttwang@polyslo.calpoly.edu