Re: Life time of an object and Reference Var

From:
Gerhard Menzl <gerhard.menzl@hotmail.com>
Newsgroups:
comp.lang.c++.moderated
Date:
9 May 2006 16:02:55 -0400
Message-ID:
<44605a9f$1@news.kapsch.co.at>
maverick wrote:

Sorry for not defining g(). But let me do it as follows:

foo& g()
{
     foo local;
     return local;
}

and lets also add a member var to class Foo say i of int type--
class Foo
{

int i;
Foo ( int j = 0 ) : i(j){}

};

now let say,
int main()
{

     Foo& ref = g();
      ref.i = 10; //?????CORE???
}

but it never core dumps.


The fact that a program doesn't core dump when you run it does not prove
that it is correct. Your program accesses an object that does not exist
anymore and exhibits undefined behaviour. Undefined behaviour can mean
anything, including that it seems to be working. You apparently get away
with it because you have a toy program that doesn't do anything besides
creating and destroying a single automatic object. But if you do
something like this in a non-trivial program, you are likely to cause
totally unpredictable effects that can be very hard to track down.

--
Gerhard Menzl

#dogma int main ()

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