Syntax changes between Swift 2.2 and 3.0
<p>I am in the process of converting a C program to Swift.  I have an unsigned int 8 bit array of 64 elements, which I can write in Swift3 as:</p>

<pre><code>let BLAKE2B_KEYBYTES = 64
var mem = [UInt8](repeating: 0, count: BLAKE2B_KEYBYTES)
</code></pre>

<p>Swift 2.2, however, requires this:</p>

<pre><code>let BLAKE2B_KEYBYTES = 64
var mem = [UInt8](count: BLAKE2B_KEYBYTES, repeatedValue: 0)
</code></pre>

<p>so, keywords are different and position is important, since count MUST precede repeatedValue in 2.2, but repeating must precede count in 3.</p>

<p>The online docs are quite sketchy on these issues.  What I am unable to locate is a definitive document on Swift 2.2 syntax.  If anyone can point me to the TRUTH on Swift 2.2, I would appreciate it.</p>