@swift-4.2.4
struct RGBA<Channel> { var red: Channel var green: Channel var blue: Channel var alpha: Channel } let rgbaArray = [RGBA<UInt8>(red: 255, green: 127, blue: 0, alpha: 255)] rgbaArray.withUnsafeBufferPointer { (rgbaBufferPointer: UnsafeBufferPointer<RGBA<UInt8>>) in rgbaBufferPointer.baseAddress!.withMemoryRebound(to: UInt8.self, capacity: rgbaBufferPointer.count * 4) { (uint8Pointer: UnsafePointer<UInt8>)in print(uint8Pointer[0]) print(uint8Pointer[1]) print(uint8Pointer[2]) print(uint8Pointer[3]) } }