Copy constructor

[Christian Christmann]

Hi,

I want to clarify that I use the copy constructor correctly.

firstclass.h:

class FirstClass
{
public:
FirstClass();
FirstClass( const FirstClass & );
[...]

private:
SecondClass *mClass;
[...]
};


firstclass.cpp:

FirstClass::FirstClass()
: mClass(NULL)
{
}

FirstClass::FirstClass( const FirstClass &copy )
{
mClass = new SecondClass (*copy.mClass);
// I am not the author of the class SecondClass but I assume
// that its copy constructor is working fine
}
[...]


Is the copy constructor for FirstClass correct?
I want to assure that the private member mClass of the new (copied)
FirstClass object is pointing to a copy of the class member copy.mClass
and avoid both FirstClass objects pointing to the same copy of mClass.

Chris

 

[=?iso-8859-1?q?Stephan_Br=F6nnimann?=]

No, the copy constructor is not correct:
If `copy' is default constructed, the you dereference a 0-pointer,
which is undefined behaviour. You'll need to protect against this.
BTW: don't forget the destructor and assignment operator
(protected against self-assignment).

regards, Stephan Brönnimann
(e-mail address removed)
Open source rating and billing engine for communication networks.