Destruction and Copying

Destructor Destructor : Special function called when object destroyed Automatically called Almost never called by hand ~CLASSNAME()

Destructors Stack objects destroyed when leave scope:

Destructors Heap objects must be destroyed manually:

Cleaning Up Memory allocated by object = potential leak

Cleaning Up Memory allocated by object = potential leak

Destructor Proper place to clean up memory object owns: New in constructor  delete in destructor

Copy Constructor Every class has a default implicit copy constructor Class::Class (const Class &other) Created invisibly and automatically

Copy Constructor Using copy constructor: p2 is copying p1

The Issue Default copy constructor for Polygon

The Issue Default copy constructor for Polygon

The Issue Default copy constructor for Polygon

The Issue Default copy constructor for Polygon

Shallow copy Shallow copy : duplicate pointers of an object Copy shares memory with original

Deep copy Deep copy : duplicate memory owned by original Copy gets own version of data

Copy Constructor Deep copy constructor Allocate own storage Copy data to it

Copy Constructor Deep copy constructor Allocate own storage Copy data to it

Copy Constructor Deep copy constructor Allocate own storage Copy data to it

Copy Constructor Deep copy constructor Allocate own storage Copy data to it

Copy Constructor Deep copy constructor Allocate own storage Copy data to it

Copy Constructor Deep copy constructor Allocate own storage Copy data to it

Book Sample

Book Example Course maintains a list of student names:

Book Example Course.h

Book Example Book Ex11.20 copy constructor Has typo – missing last 2 lines in book Should be: