Re: Basic question on exception handling in C++

From:

=?iso-8859-1?q?Erik_Wikstr=F6m?= <eriwik@student.chalmers.se>

Newsgroups:

comp.lang.c++,comp.sources.d

Date:

Tue, 12 Jun 2007 23:26:21 -0700

Message-ID:

<1181715981.383555.146630@g37g2000prf.googlegroups.com>

On 12 Juni, 19:45, ricec...@gehennom.invalid (Marcus Kwok) wrote:

In comp.lang.c++ Erik Wikstr=F6m <eri...@student.chalmers.se> wrote:

On 12 Juni, 15:04, masood.iq...@lycos.com wrote:

////// Code snippet begin /////
bool noException = true;

try
{
  // some business logic operation}

catch(std::exception& xcptn)
{
  noException = false;
  cerr << "Exception: " << xcptn.what() << " at " << __FILE__ << ","
<< __LINE__ << endl;
  cerr << "Ignoring business logic operation\n";}

catch(...)
{
  noException = false;
  cerr << "Unrecognized exception at " << __FILE__ << "," << __LINE__
<< endl;
  cerr << "Ignoring business logic operation\n";

}

Seems good to me. If you wish you can put the business logic operation
within the try-block, after the thing that might throw, since no more
statements will be executed in the try block if an exception is
thrown.

One thing that I noticed is that your (the OP's) cerr output will always
output the same line number in the message, that is, the line number of
the cerr output statement. If you want to really see where the
exception occured, you need to encode it into the exception somehow at
the throw point.

Yes, I've been searching for a good solution to this but the best I've
come up with was declaring an exception-class like this:

class myException : public std::exception
{
myException(const char* msg, const char* file, long line);
};

And using a macros like this:

#define myException(x) myException(x, __FILE__, __LINE__)

So when I throw an exception I use the macro like this:

throw myException("Illegal value");

--
Erik Wikstr=F6m