let hashTagPattern = "(?<=^|\\s)#([\\p{Alphabetic}_]\\w*)(?:\\s|$)"

let hashtagRegExp = try! NSRegularExpression(pattern: hashTagPattern,
   options: .CaseInsensitive)

let string = "#qAS ###Привет_2016 #Привет_2016 Hello #1qa #a__1 #__a__1  #qweqваваwe#qweqwe #DDSFdsf"
let nsString = string as NSString

hashtagRegExp.enumerateMatchesInString(string,
   options: NSMatchingOptions(rawValue: 0),
   range: NSRange(location: 0, length: nsString.length)) {
      result, _, _ in
      if let result = result {
         print("'\(nsString.substringWithRange(result.rangeAtIndex(1)))'")
      }
}