title: Swift function swizzling / runtime
body: <p>Before Swift, in Objective-C I would swizzle or hook methods in a class using <code>&lt;objc/runtime.h&gt;</code>.</p>
  
  <p>If anyone has any info on the topic of modifying Swift's runtime and hooking functions like CydiaSubstrate and other libraries that helped in this area, please inform me.</p>