2015-07-05 withUnsafeBufferPointer

Update 2016-10-06; a very nice (and updated for Swift 3) blog about this: http://technology.meronapps.com/2016/09/27/swift-3-0-unsafe-world-2/

I couldn't find a nice example for Array<T>.withUnsafeBufferPointer, so here's one which you can paste right into a Playground:

	//: Playground - noun: a place where people can play

	import UIKit

	var buf = [UInt8](count: 10, repeatedValue: 0)

	// Fill buffer with A to J
	for (var i = 0; i < buf.count; i++) {
		buf[i] = 65 + UInt8(i) // 65 = A
	}

	// Calculate pointer to print contents
	buf.withUnsafeBufferPointer { (pbuf: UnsafeBufferPointer<UInt8>) -> UnsafePointer<UInt8> in

		for (var j = 0; j < pbuf.count; j++) {
			let p = pbuf.baseAddress
			print(Character(UnicodeScalar((p+j).memory)))
			println(String(format:" = 0x%X", (p+j).memory))
		}
		return nil
	}

Output:

	A = 0x41
	B = 0x42
	C = 0x43
	D = 0x44
	E = 0x45
	F = 0x46
	G = 0x47
	H = 0x48
	I = 0x49
	J = 0x4A