Generic read/write method

NSStream.swift

extension NSInputStream {

    func read<T : Integer>() -> T? {
        var buffer : T = 0

        let n = withUnsafePointer(&buffer) { (p) in
            self.read(UnsafePointer<UInt8>(p), maxLength: sizeof(T))
        }

        if n > 0 {
            assert(n == sizeof(T), "read length must be sizeof(T)")
            return buffer
        } else {
            return nil
        }
    }
}

extension NSOutputStream {

    func write<T : Integer>(var source: T) -> Int {
        return withUnsafePointer(&source) { (p) in
            self.write(ConstUnsafePointer<UInt8>(p), maxLength: sizeof(T))
        }
    }

}