Re: Checking whether a pointer has been deleted
"Zedzed" <pete.cilliers@gmail.com> skrev i meddelandet
news:1149578839.671589.18020@u72g2000cwu.googlegroups.com...
Hi
Having discovered that the following is undefined:
MyClass* p = new myClass();
delete p;
if (p) //behaviour is not defined
How does one test whether a pointer has been deleted or not.
You don't - you have to know that from the program flow.
One common way is to let the pointer go out of scope after the
pointed-to object is deleted.
void f()
{
MyClass* p = new myClass();
// lots of operations
delete p;
}
The pointer p isn't visible outside of the functions, so there is no
problem.
I always
thought that that was the benefit of references over pointers - one
always had to check with pointers but with references there is never
a
need to. Or am I missing something here?
One advantage of references is that they cannot be null. For pointers
you might have to check that.
The easies way to avoid pointer troubles is not to use them!
If you put your class objects in a std::vector (or some other suitable
container), the container will manage the objects for you. Much
easier!
Bo Persson
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
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