[OSSIM] Re: Code convention question -- handling exceptional situations

[Walt B. <Wal...@jp...>]

Garrett, David,

How about something like this:

#define OSSIM_ASSERT(assertion) ossimAssert(assertion,__LINE__)

int ossimAssert(int assertion, int line) {
         if (assertion)
                 return 1;

         if (assertionCheckingMode == throwUnsatisfiedAssertions)
                 throw unsatisfiedAssertion(__LINE__);
         else if (assertionCheckingMode == notifyUnsatisfiedAssertions)
                 notifyUnsatisfiedAssertion(__LINE__);
         // else assertionCheckingMode == justLogUnsatisfiedAssertions

         logUnsatisfiedAssertion(__LINE__);
         return 0;
}

Then use like this

void useIndex(int idx) {
         if (! OSSIM_ASSERT(idx >=0))
                 idx = 0; // fix the bad idx

         continue using idx;
}

So to catch bad indices passed to useIndex while debugging, set the 
assertionCheckingMode to throwUnsatisfiedAssertions. Otherwise just 
log/notify bad indices and "fix" if possible.

Walt

At 12:53 PM 6/23/2005 -0700, Walt Bunch wrote:
>A while ago, I worked on the VPF code and observed that the approach to 
>handling exceptional situations was to silently correct errors. For 
>example, if an out of range index, e.g. -1, is passed to a method, the 
>method silently forces that index to be in range, e.g. 0. BTW, that made 
>it challenging to find some bugs.
>
>I'm working on some different code (adding set methods to class 
>ossimNitfRpcATag). Should I continue with that silent correction idiom, or 
>throw exceptions, or do something else? Is there a convention among the 
>ossim developers, or does each have his own style?
>
>Thanks,
>Walt