Declaring Pointers to Data Members

Declaring Pointers to Data Members

Although the syntax of pointers to members may seem a bit confusing at first, it is consistent and resembles the form of ordinary pointers, with the addition of the class name followed by the operator :: before the asterisk. For example, if an ordinary pointer to int looks like this:

   int * pi; 

you define a pointer to an int member of class A like this:

   class A{/**/};  int A::*pmi; // pmi is a pointer to an int  member of A

You can initialize a pointer to member:

   class A  {  public:    int num;    int x;  };  int A::*pmi = &A::num; // 1

The statement numbered 1 defines a pointer to an int member of class A and initializes it with the address of the member num. Now you can use the pointer pmi to examine and modify the value of num in any object of class A:

   A a1;  A a2;  int n = a1.*pmi; // copy the value of a1.num to n  a1.*pmi = 5; // assign the value 5 to a1.num   a2.*pmi = 6; // assign the value 6 to a2.num 

Similarly, you can access a data member through a pointer to A:

   A * pa = new A;  int n = pa->*pmi; // assign to n the value of pa->num   pa->*pmi = 5; // assign the value 5 to pa->num 

Or using a pointer to an object derived from A:

   class D : public A {};  A* pd = new D;  pd->*pmi = 5; // assign a value of 5 to pd->num
Share the Post:
XDR solutions

The Benefits of Using XDR Solutions

Cybercriminals constantly adapt their strategies, developing newer, more powerful, and intelligent ways to attack your network. Since security professionals must innovate as well, more conventional endpoint detection solutions have evolved

AI is revolutionizing fraud detection

How AI is Revolutionizing Fraud Detection

Artificial intelligence – commonly known as AI – means a form of technology with multiple uses. As a result, it has become extremely valuable to a number of businesses across

AI innovation

Companies Leading AI Innovation in 2023

Artificial intelligence (AI) has been transforming industries and revolutionizing business operations. AI’s potential to enhance efficiency and productivity has become crucial to many businesses. As we move into 2023, several

data fivetran pricing

Fivetran Pricing Explained

One of the biggest trends of the 21st century is the massive surge in analytics. Analytics is the process of utilizing data to drive future decision-making. With so much of

kubernetes logging

Kubernetes Logging: What You Need to Know

Kubernetes from Google is one of the most popular open-source and free container management solutions made to make managing and deploying applications easier. It has a solid architecture that makes

ransomware cyber attack

Why Is Ransomware Such a Major Threat?

One of the most significant cyber threats faced by modern organizations is a ransomware attack. Ransomware attacks have grown in both sophistication and frequency over the past few years, forcing

data dictionary

Tools You Need to Make a Data Dictionary

Data dictionaries are crucial for organizations of all sizes that deal with large amounts of data. they are centralized repositories of all the data in organizations, including metadata such as