Book Image

Mastering Swift 2

By : Jon Hoffman
Book Image

Mastering Swift 2

By: Jon Hoffman

Overview of this book

<p><span id="description" class="sugar_field">At their Worldwide Developer’s conference (WWDC) in 2015, Apple announced Swift 2, a major update to the innovative programming language they first unveiled to the world the year before. Swift 2 features exciting enhancements to the original iteration of Swift, acting, as Apple put it themselves as “a successor to the C and Objective-C languages.” – This book demonstrates how to get the most from these new features, and gives you the skills and knowledge you need to develop dynamic iOS and OS X applications.<br /> </span></p> <p><span id="description" class="sugar_field">Learn how to harness the newest features of Swift 2 todevelop advanced applications on a wide range of platforms with this cutting-edge development guide. Exploring and demonstrating how to tackle advanced topics such as Objective-C interoperability, ARC, closures, and concurrency, you’ll develop your Swift expertise and become even more fluent in this vital and innovative language. With examples that demonstrate how to put the concepts into practice, and design patterns and best practices, you’ll be writing better iOS and OSX applications in with a new level of sophistication and control.</span></p>
Table of Contents (24 chapters)
Mastering Swift 2
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Free Chapter
1
Taking the First Steps with Swift
2
Learning about Variables, Constants, Strings, and Operators
Index

Generic functions


Let's begin by examining the problem that generics try to solve and then we will see how generics solve this problem. Let's say that we wanted to create functions that swapped the values of two variables (as described in the introduction); however, for our application, we have a need to swap two ints, two doubles, and two strings. Without generics, this would require us to write three separate functions. The following code shows what these functions would look similar to:

func swapInts (inout a: Int, inout b: Int) {
    let tmp = a
    a = b
    b = tmp
}

func swapDoubles(inout a: Double, inout b: Double) {
    let tmp = a
    a = b
    b = tmp
}

func swapStrings(inout a: String, inout b: String) {
    let tmp = a
    a = b
    b = tmp
}

With these three functions, we can swap the original values of two ints, two doubles, and two strings. Now, let's say, as we develop our application further, we find out that we also need to swap the values of two UInt32, two floats, or...