Chapter 15, Problem 8PP

Radio Frequency IDentification (RFID) chips are small tags that can beplaced on a product. They behave like wireless barcodes and can wirelessly broadcast an identification number to a receiver. One application of RFID chips is to use them to aid in the logistics of shipping freight. Consider a shipping container full of items. Without RFID chips, a human has to manually inventory all of the items in the container to verify the contents. With an RFID chip attached to the shipping container, the RFID chip can electronically broadcast to a human the exact contents of the shipping container without human intervention.

To model this application, write a base class called ShippingContainer that has a container ID number as an integer. Include member functions to set and access the ID number. Add a virtual function called getManifest that returns an empty string. The purpose of this function is to return the contents of the shipping container.

Create a derived class called ManualShippingContainer that represents the manual method of inventorying the container. In this method, a human simply attaches a textual description of all contents of the container. For example, the description might be “4 crates of apples. 10 crates of pears.” Add a new class variable of type string to store the manifest. Add a function called setManifest that sets this string. Override the getManifest function so that it returns this string.

Create a second derived class called RFIDShippingContainer that represents the RFID method of inventorying the container. To simulate what the RFID chips would compute, create an add function to simulate adding an item to the container. The class should store a list of all added items (as a string) and their quantity using the data structures of your choice. For example, if the add function were invoked three times as follows:

rfidContainer.add("crate of pears"); // Add one crate of pears rfidContainer.add("crate of apples"); // Add one crate of apples rfidContainer.add("crate of pears"); // Add one crate of pears

At this point, the data structure should be storing a list of two items: crate of apples and crate of pears. The quantity of apples is 1and the quantity of pears is 2. Override the getManifest function so that it returns a string of all items that is built by traversing the list of items. In the example above, the return string would be “2 crate of pears. 1 crate of apples.“ Finally, write a main program that creates an array of pointers to six ShippingContainer objects. Instantiate the array with three Manual-ShippingContainer objects and three RFIDShippingContainer objects. For the ManualShippingContainer objects, you will have to invoke setManifestto set the contents. For the RFIDShippingContainer objects, you will have to invoke add to set the contents (although, if this were real, the contents of the container would “add” themselves via the RFID chips instead of requiring a human to type them in). Finally, write a loop that iterates through all ShippingContainer pointers and outputs each object’s manifestalong with the shipping container ID. This is the output that the receiver of the shipping containers would like to see.

You may need to convert an integer into a string. A simple way to do this in C++11 is: string s = to_string(intVariable);