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Swift 4 Protocol-Oriented Programming

You're reading from   Swift 4 Protocol-Oriented Programming Bring predictability, performance, and productivity to your Swift applications

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Product type Paperback
Published in Oct 2017
Publisher Packt
ISBN-13 9781788470032
Length 210 pages
Edition 3rd Edition
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Author (1):
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Jon Hoffman Jon Hoffman
Author Profile Icon Jon Hoffman
Jon Hoffman
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Toc

Table of Contents (9) Chapters Close

Preface 1. Starting with the Protocol FREE CHAPTER 2. Our Type Choices 3. Extensions 4. Generics 5. Object-Oriented Programming 6. Protocol-Oriented Programming 7. Adopting Design Patterns in Swift 8. Case Studies

Generic functions

To fully understand generics, we need to understand the problem that they are designed to solve. Let's say that we wanted to create functions that swapped the values of two variables (as described in the first part of this chapter) however, for our application, we have a need to swap the instances of two Integer types, two Double types, and two String types. Without generics, this would require us to write the following three functions:

func swapInts (a: inout Int,b: inout Int) {  
  let tmp = a 
  a = b 
  b = tmp 
} 
 
func swapDoubles(a: inout Double,b: inout Double) {  
  let tmp = a 
  a = b 
  b = tmp 
} 
 
func swapStrings(a: inout String, b: inout String) { 
  let tmp = a 
  a = b 
  b = tmp 
} 

With these three functions, we can swap the instances of two Integer types, two Double types, and two String types. Now, let's say as we develop our...

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