Lecture 4

Learning objectives

After this class (which mostly reviews C++ material that you should already know!), you should be able to:

1. Explain why templates are normally defined in .h files.
2. Define and use template functions and classes.
3. Explain how a friend function is different from others.
4. Use basic features of the STL vector and list classes.

Reading assignment

1. Chapter 1, sections 1.6-1.7 (except section 1.6.4).
2. www.sgi.com/tech/stl has a good reference on STL.
3. Lecture: Templates.

Exercises and review questions

• Exercises and review questions on current lecture's material
  1. Why are templates normally defined in .h files?
  2. Comment out the header file guards in largest.h, include largest.h twice in uselargest.cpp, and try compiling. Why does it not compile?
  3. Write a template function called average, which computes the average of an array, and give an example code demonstrating its use.
  4. Write a template class called complex, which stores a complex number. The components may either be int, float, or double. Include an operator for adding two complex numbers, and for outputting a complex number. (Note: A complex number is a pair of numbers (x,y). The sum of complex numbers c₁ = (x₁, y₁) and c₂ = (x₂, y₂) is defined as the complex number (x₁+x₂, y₁+y₂).)
  5. Why was the operator << made a friend in the Pair class?
  6. Write a program that will define a variable of STL's list type, so that it can store ints. Then insert a few integers into it, and use an iterator to go through the entire list and output its contents.

• Questions on next lecture's material
  1. None.

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Last modified: 7 Sep 2011