Gain insights into dynamic memory allocation, creating classes, and functions. Delve into inheritance, I/O, exception handling. Explore 90+ examples to master advanced C++ functionalities.

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If you’re looking to sharpen up your C++ programming skills, then you’re in the right place. You will start with learning about dynamic memory allocation, how to create classes, and constructors. 

In the latter half of the course, inheritance, functions, I/O, exception handling, and more. Throughout the course, you will study over 90 carefully designed examples aimed to enhance your understanding of the C++ language.  

By the time you finish this course, you will be able to use more advanced functionality in your C++ programs.

C++ Programming for Experienced Engineers

# Problem

Write a program to access the `struct` members using the _pointer_ to _member operators_ `.*` and `->*`.

# Sample run	 
Here’s what you should see when you run the program. 
	                        
```txt
10      3.14
10      3.14
20      6.28
20      6.28
30      9.22
40      7.33
60      8.88
```

# Coding solution		                        

Here is a solution to the problem above.


// Pointer to member operators
#include <iostream> 

struct sample 
{ 	
	int a ; 	
	float b ; 
} ;  

int main( ) 
{ 	
	sample so = { 10, 3.14f } ;
	
	int sample::*p1 = &sample::a ; 	
	float sample::*p2 = &sample::b ; 
	
	std :: cout << so.*p1 << "\t" << so.*p2 << std :: endl ;

	sample *sp ;
	sp = &so ;
	std :: cout << sp->*p1 << "\t" << sp->*p2 << std :: endl ;

	// we can even assign new values
	so.*p1 = 20 ;
	sp->*p2 = 6.28f ;
	std :: cout << so.*p1 << "\t" << so.*p2 << std :: endl ;
	std :: cout << sp->*p1 << "\t" << sp->*p2 << std :: endl ;

	sample soarr[ ] = {
		{ 30, 9.22f },
		{ 40, 7.33f },
		{ 60, 8.88f } 
		} ;

	for ( int i =0 ; i <= 2 ; i++ ) 		
		std :: cout << soarr[ i ].*p1 << "\t" << soarr[ i ].*p2 << std :: endl ;
	
	return 0 ; 
}


# Explanation	 	                        

To carry out the access and the dereferencing simultaneously, `C++` provides two operators: `.*` and `->*`. These are known as **pointer to member** operators. 
Note the definition of the pointers `p1` and `p2`:

```C++
int sample::*p1 = &sample::a ; 
float sample::*p2 = &sample::b ;
````

Consider the part before the _assignment_ operator. The **stars** indicate that `p1` and `p2` are **pointers**. `sample::` indicates they are _pointers_ to an `int` and a `float` within the `sample` structure. We have also initialized these pointers while declaring them with addresses of `a` and `b` respectively.

There really is no **address of** `sample::a` because we are referring to a _class_ and not to an _object of that class_. `&sample::a` merely produces an **offset** into the _class_. The `actual address` would be produced when we combine that **offset** with the **starting address** of a particular object. Hence `&sample::a` is nothing more than the syntax of **pointer to member**. _If we use `p1` and `p2` with one object we would get one set of values, if we use it with another we would get another set of values_. This is what is shown towards the end of the program, where we have built an _array_ of objects and accessed all objects’ elements using `p1` and `p2`. 
> In short, the _pointers to members_ are not tied with any _specific_ object.

On the left-hand side of `.*` there would always be a **structure variable** (object) or a **reference**. And on the left-hand side of `->*` there would always be a **pointer to a structure** (object).

Educate yourself about accessing the structure members using pointer to member operators.

Getting Off the Ground

Starters

Basic C++ Examples

Class Organization Examples

Class Constructor Examples

Classes and Objects Examples

More Classes and Objects Examples

Function Examples

Function Overloading Examples

Operator Overloading Examples

Free Store Examples

Inheritance Examples

Virtual Function Examples

Input Output Examples

Template Examples

Exception Handling Examples

STL Examples

Miscellaneous Examples

Conclusion

Pointer to Member Operators

Problem