c++ visual studio 2019

Do not use #include

Write a class template for a map with a fixed type for the keys string. and a template type parameter for the values. Use open hashing (chaining) with an array or vector of pointers to STL linked lists. Provide the following public member functions:

• Constructor
• Destructor
• Copy constructor
• Assignment operator
• Operator ==
• Function size that returns the number of key-value pairs in the map
• Function count that returns the number of elements with a specific key
• Function insert that inserts a key-value pair into the map
• Function at that returns a reference to the mapped value of the element identified with a specific key k. If k does not match the key of any element in the map, the function should throw an out_of_range exception.
• Function erase that removes a key-value pair identified with a specific key k. If k does not match the key of any element in the map, the function should throw an out_of_range exception.
• Function key_comp that returns a key comparison object, a function object comparing keys and returning true if the first argument (key) for comparison is less than the second and false otherwise

Provide a test program to test your template with at least two different types of values.

Hint: First implement a class for values of some fixed data type, for example integer or string, and then convert it to a class template. It makes sense to submit both the non-template and the template versions.