Question

Consider the following declaration: template class strange private: type a; type b; a. Write a statement that declares sObj to be an object of type strange such that the private member variables a and b are of type int. b. Write a statement that shows the declaration in the class strange to overload the operator == as a member function. c. Assume that two objects of type strange are equal if their corresponding member variables are equal. Write the definition of the function operator== for the class strange, which is overloaded as a member function

Short answer

Declare as `strange sObj;`. Define `operator==` inside the class and implement it by comparing `a` and `b` members.

Step-by-step solution

Declare an Object of Template Class

To declare an object named `sObj` of the template class `strange`, where the member variables `a` and `b` are of type `int`, we use the following syntax: ```cpp template strange sObj; ``` Here, `strange` specifies that the template class `strange` will use `int` as the type for its member variables.

Declare Operator Overloading in Class

To overload the `==` operator in the `strange` class, we declare a member function inside the class template that specifies how the operator should be used. The function declaration would look like this: ```cpp bool operator==(const strange& other) const; ``` This declaration specifies that the `==` operator will compare the calling object with another object of type `strange` with the same template type.

Define the Overloaded Operator==

To define the function `operator==` for the template class `strange`, you must specify how the comparison is made. Given our assumption that two `strange` objects are equal if their member variables `a` and `b` are equal, the definition will be: ```cpp template bool strange::operator==(const strange& other) const { return this->a == other.a && this->b == other.b; } ``` This code compares the `a` and `b` members of the current instance (`this`) with those of the `other` instance.

Key concepts

Operator Overloading

When working with C++, operator overloading offers a way to give additional meaning to operators when used with user-defined types such as classes. Often, this encourages the use of code that is intuitive and concise. You can define how an operator works by implementing an operator overloading function. In the context of the 'strange' class problem, we needed to overload the `==` operator to check if two objects are equal.
To achieve this, we create a member function of the class, using the keyword `bool` to denote that the function returns either `true` or `false`. The overloaded operator function for `==` might look like this:

• bool operator==(const strange<type>& other) const;

This comparison checks if the private members of two 'strange' objects are identical. Overloading enables a custom definition of equality, allowing the `==` to operate on complex types just as it does on primitive types.

Template Class

Template classes in C++ allow for the writing of code that is both flexible and reusable for different data types. A class template is a blueprint for creating classes. In this exercise, the `strange` class is a template class, designated by the `template ` declaration. This means `strange` can accommodate different data types based on where and how the class is instantiated. For example, `strange` specifies that `int` is the data type for the member variables `a` and `b`.
The template class, when instantiated, adjusts its data members accordingly. It removes the redundancy of writing similar code multiple times for different data types. So, whether it's `int`, `float`, or a custom class, the `strange` class template will offer the necessary flexibility by leveraging the data type passed during instantiation. This approach simplifies code maintenance and enhances versatility.

Member Function

A member function is a function that is defined within a class and can access its private members. In the 'strange' class, the member function `operator==` was utilized to overload the equality operator. Member functions can manipulate and retrieve the values of data members, acting on objects of that class, thus providing functionality for these objects.
In particular, the `operator==` function within the class is used to access and compare the private variables `a` and `b` with those of another instance. This highlights one of the advantages of member functions: their integrity and encapsulation within the class they belong to.
By declaring this function as a member, we ensure it has direct access to the class's internal data, and it can fully leverage the encapsulation and abstraction provided by the class, thus maintaining the logical encapsulation of data and behavior.