lab03 : C++ Big-Three Review: Constructor, Destructor, Assignment Operator

num	ready?	description	assigned	due
lab03	true	C++ Big-Three Review: Constructor, Destructor, Assignment Operator	Wed 04/25 08:00AM	Sun 04/29 11:59PM

Goals

By the end of this lab, given a description of a class containing data members that point to structures on the heap, you will be able to:

• write a correct copy constructor for the class
• write a correct destructor for the class
• write a correct assignment operator for the class

Step by Step

Step 0: Getting Started

This lab may be done solo, or in pairs.

Before you begin working on the lab, please decide if you will work solo or with a partner.

As stated in previous labs, there are a few requirements you must follow if you decide to work with a partner. I will re-iterate them here:

• Your partner must be enrolled in the same lab section as you.
• You and your partner must agree to work together outside of lab section in case you do not finish the lab during your lab section. You must agree to reserve at least two hours outside of lab section to work together if needed (preferably during an open lab hour where you can work in Phelps 3525 and ask a mentor for help). You are responsible for exchanging contact information in case you need to reach your partner.
• If you choose to work with a partner for a future lab where pair programming is allowed, then you must choose a partner you have not worked with before.
• You MUST add your partner on Gradescope when submitting your work EACH TIME you submit a file(s). After uploading your file(s) on Gradescope, there is a “Group Members” link at the bottom (or “Add Group Member” under “Groups”) where you can select the partner you are working with. Whoever uploaded the submission must make sure your partner is part of your Group. Click on “Group Members” -> “Add Member” and select your partner from the list.
• You must write your Name(s) and Perm number on each file submitted to Gradescope.

Once you and your partner are in agreement, choose an initial driver and navigator, and have the driver log into their account.

Step 1: Copying some programs from my directory

Visit the following web link—you may want to use “right click” (or “control-click” on Mac) to bring up a window where you can open this in a new window or tab:

http://cs.ucsb.edu/~richert/cs32/misc/lab03/

You should see a listing of several C++ programs. We are going to copy those into your~/cs32/lab03 directory all at once with the following command:

Note: If you get the error message:

then it probably means you didn’t create a ~/cs32/lab03 directory yet. So do that first.

The * symbol in this command is a “wildcard”—it means that we want all of the files from the source directory copy be copied into the destination directory namely ~/cs32/lab03.

After doing this command, if you cd into ~/cs32/lab03 and use the ls command, you should see several files in your ~/cs32/lab03 directory—the same ones that you see if you visit the link http://cs.ucsb.edu/~richert/cs32/misc/lab03/

If so, you are ready to move on to the next step.

If you don’t see those files, go back through the instructions and make sure you didn’t miss a step. If you still have trouble, ask your TA for assistance.

Step 2 Getting the code to pass the tests

In this week’s lab, you have the following files:

• Makefile
• student.h, student.cpp
• studentRoll.h, studentRoll.cpp
• studentTest00.cpp, etc.
• studentRollTest00.cpp, etc.

Your job is, as usual, get all the test cases to pass. This involves implementing the “big three”: Copy Constructor, Overloaded Assignment Operator, and Destructor.

In addition to the regular test cases, there are also “leakTests”. This involves running a utility called valgrind on your code to see whether there are any memory leaks, or other problems involving memory management. You will only pass the tests if your code has proper memory management.

You will submit only the student.cpp and studentRoll.cpp files. As a result, there are two quite annoying things that you’ll just have to put up with:

• In the Student class, the name attribute is implemented with a C-string that is allocated with dynamic memory on the heap. This is annoying. You might prefer to use the std::string class. Of course you would. But, that’s not the point of this assignment. The point of this assignment is to know whether you can manage memory properly.
• In the StudentRoll class, the list of students is a linked list of structs rather than an std::list<Student> or std::vector<Student> or something. This is indeed annoying. Tough. We are training you for the situation where you don’t have any choice, but have to work with the data structures you are given.

In certain later assignments, you will be given the freedom to choose whatever data structure or implementation is appropriate. You’ll be able to decide whether to use std::string, or C-strings, whether to use array or std::vectors, etc. This is not one of those assignments.

Suggested way to proceed

I suggest proceeding in the following steps:

1. Work on each test file for student, getting those tests to pass, i.e. testStudent00.cpp, testStudent01.cpp, etc.
   • To get these to pass, you need to implement, possibly among other things, the Copy Constructor and Overloaded Assignment Operator for Student.
2. Then, try to get the leak tests to pass as they pertain to Student, i.e.
   • make lts00
   • make lts01
   • make lts02
   • make lts03
   • This will require implementing the destructor for Student
3. Work on each test file for StudentRoll, getting those tests to pass, i.e. testStudentRoll00.cpp, testStudentRoll01.cpp, etc.
   • To get these to pass, you need to implement, possibly among other things, the Copy Constructor and Overloaded Assignment Operator for StudentRoll
4. Then, try to get the leak tests for StudentRoll to pass, i.e.
   • make ltsr00
   • make ltsr01
   • make ltsr02
   • This will require implementing the destructor for StudentRoll

How do I know if I’m done?

When you are done, you should be able to do both of the following, and see no error messages:

• make tests
• make leaktests

Step 3: Submitting via Gradescope

The lab assignment “Lab03” should appear in your Gradescope dashboard in CMPSC 32. If you haven’t submitted anything for this assignment yet, Gradescope will prompt you to upload your files.

For this lab, you will need to upload your modified files (i.e. student.cpp and studentRoll.cpp). You either can navigate to your file, “drag-and-drop” them into the “Submit Programming Assignment” window, or even use a GitHub repo to submit your work.

If you already submitted something on Gradescope, it will take you to their “Autograder Results” page. There is a “Resubmit” button on the bottom right that will allow you to update the files for your submission.

For this lab, if everything is correct, you’ll see a successful submission passing all of the autograder tests.

Remember to add your partner to Groups Members for this submission on Gradescope if applicable. At this point, if you worked in a pair, it is a good idea for both partners to log into Gradescope and check if you can see the uploaded files for Lab03.