Pointers to Members - Advanced Programming - Lecture Slides, Slides of Computer Science

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Classes

this & pointers to members

Self-Reference -- this

• A Pointer to the Object, which is Used in Member Function Invocation -- this
• A Return Pointer to that Object
• Direct Reference to Members of the Object in a Member Function is Possible
• this is NOT Available to friend Functions

this -- Example 2

• /* Use of "this" in a doubly linked list */ class student{ int ss; student *next; student *prev; public: void append(student *); };

this -- Example 2

• void student::append(student *ip){ ip->next = next; ip->prev = this; next->prev = ip; next = ip; }
• void my_function(student *new_student){ student *head; // ... head->append(new_student); }

this -- Example 2

Head

( this )

ss prev next

ss prev next

ss prev next

ss prev next ip

After configuration

*void student::append(student ip){ ip->next = next; ip->prev = this; next->prev = ip; next = ip;

Pointers to Members

• Pointers to Data Members
• Pointers to Member Functions

Pointers to Member Functions -- Example

• class student{public: int ss, credits;student():ss(0), credits(0){} int return_ss(){return ss;}int return_credits(){return credits;} };
• main(){// "pmf" is a pointer to a member function of "student" that returns int int (student::pmf)();pmf = student::return_ss; // "pmf" is pointing to "return_ss()" student s1;cout << (s1.pmf)() << endl; //"s1.return_ss()" is invoked "return_credits()"pmf = student::return_credits; // "pmf" is pointing to } cout << (s1.*pmf)() << endl; //"s1.return_credits()" is invoked