CPSC 421-020 Object-Oriented Programming (OOP) Spring 2023

Week 10 Class 18 Thu Mar 16 Posted: Mar 16

After Class

• Project 3 If you have a large number of variables to pass via capture, you can pass all of them (and all variables in scope) using the capture default, [&].

• Project 3 Pass std::string_view as an IN parameter by value, not const reference:

  Use	Don't Use

  std::string_view consists of a pointer (to the actual memory) and a size, and is equivalent to the following:

  Since this is so small, passing by value is efficient. While it takes the same number of assembly operations, it requires an extra pointer dereference, and timings show they are equivalent.

Announcements

• Midterm

  Midterm scores and feedback are posted in Brightspace:

  • Overall score in Grades under Midterm
  • Copy of your test as a pdf in Assignments under Midterm Feedback
  • Scores and feedback for each question as a pdf in Assignments under Midterm Feedback

• Project 3

  • You are allowed one @stereotype get method for total bytes.

Class

• Notes: UML Association
• Exercise 46: UML Association Crossword
• Notes: UML Generalization
• Exercise 47: UML Generalization Crossword
• Notes: Dispatch
• Exercise 48: Dispatch Crossword

• Exercise 49: Base

  virtual methods in C++ support dynamic polymorphism. Dynamic polymorphism only occurs with pointers and references to objects, passing by value is not polymorphic.

  

  The classes in this exercise are Base, Derived which inherits from Base, and DerivedDerived which inherits from Derived. So Derived is a Base, and DerivedDerived is a Derived and therefore also is a Base.

  The method m1() is not virtual, so it does not provide for polymorphism.

  The method m2() is virtual, so it does provide for polymorphism.

   

  Complete the assertions in the code that indicate (via a string) which method is called, e.g., for m1() is it "Base::m1()", "Derived::m1()", or "DerivedDerived::m1()"?

  Complete each assertion one at a time in order, compiling and running the program (i.e., make run) after each assertion is completed. The assertion you edited should pass, and you should be onto the next assertion.

  You are required to commit for each block of statements in the main program.

  The GitHub Classroom link is in Brightspace.

All exercises are due by 4:30 pm on Monday, Mar 27