Description
In this workshop, you store polymorphic objects in an STL container.
LEARNING OUTCOMES
Upon successful completion of this workshop, you will have demonstrated the abilities to
• manage polymorphic objects using the vector container of the STL
• move a dynamically allocated object into a container
• code a range-based iteration on the objects in a container
• report and handle an exception
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 three modules:
• w6 (supplied)
• Sale
• Product
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 Sales.dat
Product No Cost
10012 34.56
10023 45.67
10234 12.32
10056 67.54
10029 54.12
10034 96.30
Total 310.51
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
10012 34.56
10023 45.67
10234 12.32
10056 67.54
10029 54.12
10034 96.30
Each record in the file consists of a product number and its price.
Product Module
Design and code an inheritance hierarchy named iProduct for holding data on products for sale.
Your interface to the hierarchy uses the field width (int FW) defined outside the translation unit
and specifies the following public member function requirements:
• double price() const – a query that returns the price of a product.
• void display(std::ostream& os) const – a query that displays the information about the
product. Use the field width defined in the supplied w6 module.
Your interface also includes prototypes to meet the following global function requirements:
• operator<<(std::ostream& os, const iProduct& p) – a helper that inserts the product
information into the stream os.
• iProduct* readRecord(std::ifstream& file); – a function that reads a single record from
file object file, allocates memory for a product in the hierarchy, stores the information
read into the product object and returns its address.
A concrete class named Product implements this interface and includes
• a constructor that receives and stores the product number and its price before tax.
Sale Module
Design and code a class named Sale for managing a sequence of iProduct objects. Your class
design includes the following public member functions:
• A single argument constructor that receives the address of an unmodifiable C-style null
terminated string that contains the name of the file holding records of iProduct type.
This function opens the file, reads one record from the file, moves that record into an
STL container and keeps reading records until there are none left to be read. If this
function fails to open the file, it throws an exception with an appropriate message.
• void display(std::ostream& os) const – a query that displays the products that make up
the sale and the total price in the format shown above. In coding this function use a
range based for and the field width specified outside the translation unit.
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_w6_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 to include tax:
• Product (from in-lab)
• Sale (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 Sales.dat
Product No Cost Taxable
10012 34.56
10023 45.67 HST
10234 12.32 PST
10056 67.54
10029 54.12 HST
10034 96.30
Total 324.47
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
10012 34.56
10023 45.67 H
10234 12.32 P
10056 67.54
10029 54.12 H
10034 96.30
Each record in the file consists of a product number, its price and optionally its taxable status.
Product Module
Derive a class named TaxableProduct from your Product class to add taxation functionality to
the hierarchy. Your derived class includes
• an enumeration list of tax types and a class variable with corresponding rates
o HST 0.13
o PST 0.08
Your derived class also includes the following upgrades:
• A three-argument constructor that receives and stores the product number, its price
and its tax status.
• double price() const – a query that returns the price of a product tax included.
• void display(std::ostream& os) const – a query that displays the information about the
product and appends the tax status as shown in the example above.
• iProduct* readRecord(std::ifstream& file) – this function reads a single record from file
object file, allocates memory for a product in the hierarchy, stores the information read
into the product object and returns its address. The information includes the product
number and price and optionally the tax status as shown in the sample input above. If
the record does not include a tax status character this function allocates memory for a
Product object. If the record has a tax status character this function allocates memory
for a TaxableProduct object.
Sale Module
Upgrade the Sale module to include “Taxable” in the heading for displaying the product data as
shown in the sample output above.
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 reason for using the vector container rather than any other available in the STL.
• Why there is no need to deallocate the dynamically allocated memory in your own code.
• How the range-based for simplifies coding in this case.
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_w6_home
and follow the instructions. Replace XXX with the section letter(s) specified by your instructor.
