Class Versus Struct

Question

In C++ and other influenced languages there is a construct called Structure (struct) and we all know the class. Both are capable of holding functions and variables. some differences are
1. Class is given memory in heap and struct is given memory in stack
2. in class variable are private by default and in struct thy are public

My question is that struct was somehow abandoned for Class. Why? other that abstraction, a struct can do all the same stuff a class does. Then why abandon it?

Answer 1

It is not abandoned at all. In fact, even modern languages like C# which make heavy use of class still offer you struct. As for when it's useful to choose one over the other, I refer you to this article:

Choosing Between Classes and Structures

Quoted from the MSDN article:

Consider defining a structure instead of a class if instances of the type are small and commonly short-lived or are commonly embedded in other objects.

Do not define a structure unless the type has all of the following characteristics:

• It logically represents a single value, similar to primitive types (integer, double, and so on).
• It has an instance size smaller than 16 bytes.
• It is immutable.
• It will not have to be boxed frequently.

Answer 2

You are mistaken about C++: the only significant difference between class and struct is the default access specifier difference. Struct and class are for all intents and purposes synonyms, I believe struct is kept around for backwards compatibility to C.

Answer 3

the language D has created a greater distinction between class and struct

a struct in d is nothing but a stack allocated data record with some functions you can call on it (there is no option for inheritance unless you use a enum + union setup i.e. implement the polymorfism yourself) that is passed by value

a class is like we are used to: virtual functions, heap allocation, (single) inheritance, passed by ref