Description
In this workshop, you code a function object, a lambda expression, and exception handling.
LEARNING OUTCOMES
Upon successful completion of this workshop, you will have demonstrated the abilities to
• design and code a templated class that allocates and deallocates dynamic memory
• design and code a function object
• design and code a lambda expression
• code a member function that receives the address of another function to execute
• throw exceptions of different types
• distinguish exception types
SUBMISSION POLICY
The in-lab section is to be completed during your assigned lab section. It is to be completed
and submitted by the end of the workshop period. If you attend the lab period and cannot
complete the in-lab portion of the workshop during that period, ask your instructor for
permission to complete the in-lab portion after the period. If you do not attend the workshop,
you can submit the in-lab section along with your at-home section (see penalties below). The
at-home portion of the lab is due on the day that is four days after your scheduled in-lab
workshop (23:59:59) (even if that day is a holiday).
All your work (all the files you create or modify) must contain your name, Seneca email and
student number.
You are responsible to back up your work regularly.
Late Submission Penalties:
• In-lab portion submitted late, with at-home portion: 0 for in-lab. Maximum of 7/10 for the
entire workshop.
• If any of in-lab, at-home or reflection portions is missing, the mark for the workshop will be
0/10.
SPECIFICATIONS – IN LAB
The solution to the in-lab part of this workshop consists of four modules:
• w5 (supplied)
• KVList
• KVPair
• Taxable
Enclose all your source code within the sict namespace and include the necessary guards in
each header file. The output from your executable running Visual Studio with the following
command line argument should look like
Command Line : C:\Users\…\Debug\in_lab.exe PriceList.txt
Price List with G+S Taxes Included
==================================
Description: Price Price+Tax
Soap : 1.29 1.46
Detergent : 3.49 3.94
Lysol : 3.59 4.06
Kleenex : 0.50 0.56
The input for testing your solution is stored in a user-prepared file. The name of the file is
specified on the command line as shown in red above. The file is supplied with this workshop.
The contents of this file are
Soap 1.29
Detergent 3.49
Lysol 3.59
Kleenex 0.50
Each record in the file consists of key and value fields. For the PriceList.txt file, the name of
the product is the key and the price of the product is its value.
KVPair Module
Design and code a templated class named KVPair for managing a single key-value pair. Your
class design includes the following public member functions:
• A default constructor that places the object in a safe empty state.
• KVPair(const K&, const V&) – a two-argument constructor that receives a reference to
an unmodifiable key and a reference to an unmodifiable value. This function stores the
received key and value in the object’s instance variables.
• template
that inserts into the output stream os the current object’s key (left-justified), a single
space, a colon, a single space, the object’s value and the object’s value converted
through the function f (both right justified) as shown above. If the current object is in a
safe empty state, this query does nothing. The field width for the object’s values is
externally defined.
KVList Module
Design and code a templated class named KVList for managing a dynamically allocated list of T
objects. Your class design includes the following public member functions:
• A default constructor that places the object in a safe empty state.
• KVList(int n) – a single-argument constructor that receives the number of objects in the
list and allocates memory for those objects. If the number received is not positivevalued your constructor places the object in a safe empty state.
• KVList(KVList&&) – a move constructor.
• ~KVList() – a destructor.
• const T& operator[](size_t i) const – a subscripting operator that returns an
unmodifiable reference to the i-th element in the list. For the in-lab part of this
workshop, you may assume that the index is not out of bounds.
• template
that inserts into the output stream os on a separate line each object in the list as shown
above. If there are no objects in the list or the object is in a safe empty state, this query
does nothing.
• push_back(const T& t) – a modifier that receives an unmodifiable reference to a T
object t and if there is room in the list, adds the object t to the list. If the list is full, this
function does nothing.
Your design disables copy and move assignment operations and copy construction of the list.
Taxable Module
Design and code a functor (function object) named Taxable that receives a value and returns
the sum of the value with the tax on it. Your class design includes the following public member
functions:
• Taxable(float) A one-argument constructor that receives the prescribed tax rate and
stores it in an unmodifiable instance variable.
• float operator()(float) A function call operator that receives a price and returns the sum
of the price and the tax added to it.
In-Lab Submission (30%)
To test and demonstrate execution of your program use the same data as shown in the output
example above.
Upload your source code to your matrix account. Compile and run your code using the latest
version of the gcc compiler and make sure that everything works properly.
Then, run the following command from your account: (replace profname.proflastname
with your professor’s Seneca userid)
~profname.proflastname/submit 345XXX_w5_lab
and follow the instructions. Replace XXX with the section letter(s) specified by your instructor.
SPECIFICATIONS – AT HOME
The at-home part of this workshop updates the following modules:
• w5 (from in-lab)
• KVList (from in-lab)
• KVPair (from in-lab)
The output from your executable running Visual Studio with the following command line
argument should look like
Command Line : C:\Users\…\Debug\at_home.exe PriceList.txt Student.txt
Price List with G+S Taxes Included
==================================
Description: Price Price+Tax
Soap : 1.29 1.46
Detergent : 3.49 3.94
Lysol : 3.59 4.06
Kleenex : 0.50 0.56
Student List Letter Grades Included
===================================
Student No : Grade Letter
203342102 : 67.50 C+
923416789 : 83.40 A
310654789 : 56.70 D+
201352234 : 63.40 C
The input for testing your solution is stored in two user-prepared files. The names of the files
are specified on the command line as shown in red above. Two files are supplied with this
workshop.
KVList Module
Add exception reporting to this module to cover the following cases:
• The number of elements received in the constructor is not positive-valued
• The index passed to the subscripting operator is out-of-bounds
You will need to add code to handle these exceptions in the calling function (w5).
w5 Module
Add code to process a list of student grades and convert their values to letter grades. Note that
the letter grades without a plus consist of the letter followed by a single space. In other words,
all letter grades consist of two characters, excluding the null byte.
The code for this grade list is similar to that for the price list. The key is an int and the grade is a
float. Use a lambda expression instead of a functor for your conversion function.
Introduce exception handling into your module wherever it is appropriate. Your exceptions
should include command line errors as well as errors generated by the createList() function.
Call the exit() function where appropriate, using a different exit value for each type of error.
Reflection
Study your final solution, reread the related parts of the course notes, and make sure that you
have understood the concepts covered by this workshop. This should take no less than 30
minutes of your time. Explain in your own words what you have learned in completing this
workshop. Include in your explanation but do not limit it to the following points (40%):
• The difference between the implementations of a functor and a lambda expression.
• A list of the exceptions that you have reported and the cases where you terminated
execution normally.
To avoid deductions, refer to code in your solution as examples to support your explanations.
Include all corrections to the Quiz(zes) you have received (30%).
At-Home Submission (70%)
To test and demonstrate execution of your program use the same data as shown in the output
example above.
Upload your source code to your matrix account. Compile and run your code using the latest
version of the gcc compiler and make sure that everything works properly.
Then, run the following command from your account: (replace profname.proflastname
with your professor’s Seneca userid)
~profname.proflastname/submit 345XXX_w5_home
and follow the instructions. Replace XXX with the section letter(s) specified by your instructor.
