C++ for Lazy Programmers: Quick, Easy, and Fun C++ for Beginners

© Will Briggs 2019

W. BriggsC++ for Lazy Programmershttps://doi.org/10.1007/978-1-4842-5187-4_20

20. Templates

Will Briggs¹ 

(1)

Lynchburg, VA, USA

 

Would I write a function or class that takes ints, and another just like it except it takes strings, and another just like it except it takes Ubergeeks? That doesn’t sound lazy! This chapter enables us to write it once, using templates.

Function templates

Recall this function for swapping ints, from Chapter 8:

void swap (int& arg1, int& arg2)

{

      int temp = arg2; arg2 = arg1; arg1 = temp;

}

That’s fine for int, but what if I want doubles? strings? Heffalumps? I don’t want to write new versions for every type I encounter! Here’s the fix.

template <typename T>

void swap (T& arg1, T& arg2)

{

      T temp = arg2; ...