postfix increment/decrement and prefix increment/decrement, for those who will miss them in Swift 3

postfix and prefix increment decrement.swift

postfix operator +++ {}
postfix func +++(inout left: Int) -> Int {
	defer {left += 1}
	return left
}
postfix operator --- {}
postfix func ---(inout left: Int) -> Int {
	defer {left -= 1}
	return left
}
prefix operator +++ {}
prefix func +++(inout right: Int) -> Int {
	right += 1
	return right
}
prefix operator --- {}
prefix func ---(inout right: Int) -> Int {
	right -= 1
	return right
}