Re: Assertion vs Exception Handling

From:

"Daniel T." <daniel_t@earthlink.net>

Newsgroups:

comp.lang.c++

Date:

Tue, 09 Mar 2010 09:52:06 -0500

Message-ID:

<daniel_t-809A9E.09520609032010@70-3-168-216.pools.spcsdns.net>

DT <dongta.hds@gmail.com> wrote:

1. I have a long array and I want to check element of the array fails
my test, for example:

for (int i ...) {
    if (a[i]==0) {
        cout << "failed " << i << "\n"; break;
    }
}

Plus, I only want to compile this error checking code in the debug
mode. If I can use assertion, how to do it? Otherwise, should I use
exception handling and how?

Read section 24.3.7.2 in "The C++ Programming Language" by Stroustrup.

2. If an assertion fails before the cleanup code (i.e. freeing the
pointers), would I experience memory leak? If so, how to avoid such
problems?

You don't have to worry about memory leaks, but there may be other
cleanup or state saving that needs to happen that wont.

For your example, I suggest something like (a variation of Stroustrup's
code):

template <typename X>
inline void Assert(bool assertion)
{
   if (!assertion)
      throw X();
}

Then where needed:

   Assert<std::exception>(NDEBUG || find(a.begin(), a.end(), 0) ==
a.end());