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

num	ready?	description	assigned	due
lab03	true	C++ Big-Three Review: Constructor, Destructor, Assignment Operator	Mon 09/27 08:00AM	Fri 12/10 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 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/s18/lab03/

You should see a listing of several C++ programs. We are going to copy those into your~/cmptgcs 1a/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 ~/cmptgcs 1a/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 ~/cmptgcs 1a/lab03.

After doing this command, if you cd into ~/cmptgcs 1a/lab03 and use the ls command, you should see several files in your ~/cmptgcs 1a/lab03 directory—the same ones that you see if you visit the link http://cs.ucsb.edu/~richert/cs32/misc/s18/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 CMPTGCS 1A. 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.