Create a cpp file named "main. cpp$"$ that defines

$$ a bool function named IsWord$()$ that takes a constant string reference parameter. It returns true if the parameter represents a word; otherwise, it returns false. A word is a string that consists only of letter characters.

$$ a string function named Capitalize$()$ that takes a constant string reference parameter. If the parameter represents a word, it returns a capitalized version of the parameter; otherwise, it returns an empty string.

Extra Credit

Create a header file named "Extra.h$"$ that defines a class named WholeSquare that contains

a private int field named value.

a public default constructor that assigns $1$ to value.

a public copy constructor.

a public int constant method named GetLength$()$ that takes no parameters and returns value.

a public void method named SetLength$()$ that takes an int parameter and assigns the parameter to value only if the parameter is positive.

a public string constant method named ToString$()$ that takes no parameters and returns a $nn$ square string of asterisks where $n$ is the value of value.