tôi đã quá thất vọng với phương pháp khó hiểu Swift của thông số bitPattern: và truncatingBitPattern: và không có khả năng của tôi để nhớ cái nào để sử dụng khi nào, mà tôi tạo ra các lớp sau có chứa một số lượng lớn các phương pháp chuyển đổi.
Tôi không nhất thiết khuyên bạn nên đưa điều này vào chương trình của mình. Tôi chắc rằng nhiều người sẽ nói rằng Swift đang cố gắng bảo vệ chúng ta khỏi chính chúng ta và phá hoại nỗ lực đó là câm.Vì vậy, có lẽ bạn nên giữ tập tin này ở đâu đó như một loại cheat sheet để bạn có thể nhanh chóng xác định làm thế nào để thực hiện một chuyển đổi, và sao chép các tham số vào chương trình của bạn khi cần thiết.
Ngẫu nhiên, JDI là viết tắt của "chỉ cần thực hiện".
/// Class containing a large number of static methods to convert an Int to a UInt or vice-versa, and
/// also to perform conversions between different bit sizes, for example UInt32 to UInt8.
///
/// Many of these "conversions" are trivial, and are only included for the sake of completeness.
///
/// A few of the conversions involving Int and UInt can give different results when run on 32-bit
/// and 64-bit systems. All of the conversion where the bit size of both the source and the target
/// are specified will always give the same result independent of platform.
public class JDI {
// MARK: - To signed Int
// To Int8
public static func ToInt8(_ x : Int8) -> Int8 {
return x
}
public static func ToInt8(_ x : Int32) -> Int8 {
return Int8(truncatingBitPattern: x)
}
public static func ToInt8(_ x : Int64) -> Int8 {
return Int8(truncatingBitPattern: x)
}
public static func ToInt8(_ x : Int) -> Int8 {
return Int8(truncatingBitPattern: x)
}
public static func ToInt8(_ x : UInt8) -> Int8 {
return Int8(bitPattern: x)
}
public static func ToInt8(_ x : UInt32) -> Int8 {
return Int8(truncatingBitPattern: x)
}
public static func ToInt8(_ x : UInt64) -> Int8 {
return Int8(truncatingBitPattern: x)
}
public static func ToInt8(_ x : UInt) -> Int8 {
return Int8(truncatingBitPattern: x)
}
// To Int32
public static func ToInt32(_ x : Int8) -> Int32 {
return Int32(x)
}
public static func ToInt32(_ x : Int32) -> Int32 {
return x
}
public static func ToInt32(_ x : Int64) -> Int32 {
return Int32(truncatingBitPattern: x)
}
public static func ToInt32(_ x : Int) -> Int32 {
return Int32(truncatingBitPattern: x)
}
public static func ToInt32(_ x : UInt8) -> Int32 {
return Int32(x)
}
public static func ToInt32(_ x : UInt32) -> Int32 {
return Int32(bitPattern: x)
}
public static func ToInt32(_ x : UInt64) -> Int32 {
return Int32(truncatingBitPattern: x)
}
public static func ToInt32(_ x : UInt) -> Int32 {
return Int32(truncatingBitPattern: x)
}
// To Int64
public static func ToInt64(_ x : Int8) -> Int64 {
return Int64(x)
}
public static func ToInt64(_ x : Int32) -> Int64 {
return Int64(x)
}
public static func ToInt64(_ x : Int64) -> Int64 {
return x
}
public static func ToInt64(_ x : Int) -> Int64 {
return Int64(x)
}
public static func ToInt64(_ x : UInt8) -> Int64 {
return Int64(x)
}
public static func ToInt64(_ x : UInt32) -> Int64 {
return Int64(x)
}
public static func ToInt64(_ x : UInt64) -> Int64 {
return Int64(bitPattern: x)
}
public static func ToInt64(_ x : UInt) -> Int64 {
return Int64(bitPattern: UInt64(x)) // Does not extend high bit of 32-bit input
}
// To Int
public static func ToInt(_ x : Int8) -> Int {
return Int(x)
}
public static func ToInt(_ x : Int32) -> Int {
return Int(x)
}
public static func ToInt(_ x : Int64) -> Int {
return Int(truncatingBitPattern: x)
}
public static func ToInt(_ x : Int) -> Int {
return x
}
public static func ToInt(_ x : UInt8) -> Int {
return Int(x)
}
public static func ToInt(_ x : UInt32) -> Int {
if MemoryLayout<Int>.size == MemoryLayout<Int32>.size {
return Int(Int32(bitPattern: x)) // For 32-bit systems, non-authorized interpretation
}
return Int(x)
}
public static func ToInt(_ x : UInt64) -> Int {
return Int(truncatingBitPattern: x)
}
public static func ToInt(_ x : UInt) -> Int {
return Int(bitPattern: x)
}
// MARK: - To unsigned Int
// To UInt8
public static func ToUInt8(_ x : Int8) -> UInt8 {
return UInt8(bitPattern: x)
}
public static func ToUInt8(_ x : Int32) -> UInt8 {
return UInt8(truncatingBitPattern: x)
}
public static func ToUInt8(_ x : Int64) -> UInt8 {
return UInt8(truncatingBitPattern: x)
}
public static func ToUInt8(_ x : Int) -> UInt8 {
return UInt8(truncatingBitPattern: x)
}
public static func ToUInt8(_ x : UInt8) -> UInt8 {
return x
}
public static func ToUInt8(_ x : UInt32) -> UInt8 {
return UInt8(truncatingBitPattern: x)
}
public static func ToUInt8(_ x : UInt64) -> UInt8 {
return UInt8(truncatingBitPattern: x)
}
public static func ToUInt8(_ x : UInt) -> UInt8 {
return UInt8(truncatingBitPattern: x)
}
// To UInt32
public static func ToUInt32(_ x : Int8) -> UInt32 {
return UInt32(bitPattern: Int32(x)) // Extend sign bit, assume minus input significant
}
public static func ToUInt32(_ x : Int32) -> UInt32 {
return UInt32(bitPattern: x)
}
public static func ToUInt32(_ x : Int64) -> UInt32 {
return UInt32(truncatingBitPattern: x)
}
public static func ToUInt32(_ x : Int) -> UInt32 {
return UInt32(truncatingBitPattern: x)
}
public static func ToUInt32(_ x : UInt8) -> UInt32 {
return UInt32(x)
}
public static func ToUInt32(_ x : UInt32) -> UInt32 {
return x
}
public static func ToUInt32(_ x : UInt64) -> UInt32 {
return UInt32(truncatingBitPattern: x)
}
public static func ToUInt32(_ x : UInt) -> UInt32 {
return UInt32(truncatingBitPattern: x)
}
// To UInt64
public static func ToUInt64(_ x : Int8) -> UInt64 {
return UInt64(bitPattern: Int64(x)) // Extend sign bit, assume minus input significant
}
public static func ToUInt64(_ x : Int32) -> UInt64 {
return UInt64(bitPattern: Int64(x)) // Extend sign bit, assume minus input significant
}
public static func ToUInt64(_ x : Int64) -> UInt64 {
return UInt64(bitPattern: x)
}
public static func ToUInt64(_ x : Int) -> UInt64 {
return UInt64(bitPattern: Int64(x)) // Extend sign bit if necessary, assume minus input significant
}
public static func ToUInt64(_ x : UInt8) -> UInt64 {
return UInt64(x)
}
public static func ToUInt64(_ x : UInt32) -> UInt64 {
return UInt64(x)
}
public static func ToUInt64(_ x : UInt64) -> UInt64 {
return x
}
public static func ToUInt64(_ x : UInt) -> UInt64 {
return UInt64(x) // Does not extend high bit of 32-bit input
}
// To UInt
public static func ToUInt(_ x : Int8) -> UInt {
return UInt(bitPattern: Int(x)) // Extend sign bit, assume minus input significant
}
public static func ToUInt(_ x : Int32) -> UInt {
return UInt(truncatingBitPattern: Int64(x)) // Extend sign bit, assume minus input significant
}
public static func ToUInt(_ x : Int64) -> UInt {
return UInt(truncatingBitPattern: x)
}
public static func ToUInt(_ x : Int) -> UInt {
return UInt(bitPattern: x)
}
public static func ToUInt(_ x : UInt8) -> UInt {
return UInt(x)
}
public static func ToUInt(_ x : UInt32) -> UInt {
return UInt(x)
}
public static func ToUInt(_ x : UInt64) -> UInt {
return UInt(truncatingBitPattern: x)
}
public static func ToUInt(_ x : UInt) -> UInt {
return x
}
}
Dưới đây là một số mã kiểm tra:
public func doTest() {
// To Int8
assert(JDI.ToInt8(42 as Int8) == 42)
assert(JDI.ToInt8(-13 as Int8) == -13)
assert(JDI.ToInt8(42 as Int32) == 42)
assert(JDI.ToInt8(257 as Int32) == 1)
assert(JDI.ToInt8(42 as Int64) == 42)
assert(JDI.ToInt8(257 as Int64) == 1)
assert(JDI.ToInt8(42 as Int) == 42)
assert(JDI.ToInt8(257 as Int) == 1)
assert(JDI.ToInt8(42 as UInt8) == 42)
assert(JDI.ToInt8(0xf3 as UInt8) == -13)
assert(JDI.ToInt8(42 as UInt32) == 42)
assert(JDI.ToInt8(0xfffffff3 as UInt32) == -13)
assert(JDI.ToInt8(42 as UInt64) == 42)
assert(JDI.ToInt8(UInt64.max - 12) == -13)
assert(JDI.ToInt8(42 as UInt) == 42)
assert(JDI.ToInt8(UInt.max - 12) == -13)
// To Int32
assert(JDI.ToInt32(42 as Int8) == 42)
assert(JDI.ToInt32(-13 as Int8) == -13)
assert(JDI.ToInt32(42 as Int32) == 42)
assert(JDI.ToInt32(-13 as Int32) == -13)
assert(JDI.ToInt32(42 as Int64) == 42)
assert(JDI.ToInt32(Int64(Int32.min) - 1) == Int32.max)
assert(JDI.ToInt32(42 as Int) == 42)
assert(JDI.ToInt32(-13 as Int) == -13)
assert(JDI.ToInt32(42 as UInt8) == 42)
assert(JDI.ToInt32(0xf3 as UInt8) == 243)
assert(JDI.ToInt32(42 as UInt32) == 42)
assert(JDI.ToInt32(0xfffffff3 as UInt32) == -13)
assert(JDI.ToInt32(42 as UInt64) == 42)
assert(JDI.ToInt32(UInt64.max - 12) == -13)
assert(JDI.ToInt32(42 as UInt) == 42)
assert(JDI.ToInt32(UInt.max - 12) == -13)
// To Int64
assert(JDI.ToInt64(42 as Int8) == 42)
assert(JDI.ToInt64(-13 as Int8) == -13)
assert(JDI.ToInt64(42 as Int32) == 42)
assert(JDI.ToInt64(-13 as Int32) == -13)
assert(JDI.ToInt64(42 as Int64) == 42)
assert(JDI.ToInt64(-13 as Int64) == -13)
assert(JDI.ToInt64(42 as Int) == 42)
assert(JDI.ToInt64(-13 as Int) == -13)
assert(JDI.ToInt64(42 as UInt8) == 42)
assert(JDI.ToInt64(0xf3 as UInt8) == 243)
assert(JDI.ToInt64(42 as UInt32) == 42)
assert(JDI.ToInt64(0xfffffff3 as UInt32) == 4294967283)
assert(JDI.ToInt64(42 as UInt64) == 42)
assert(JDI.ToInt64(UInt64.max - 12) == -13)
assert(JDI.ToInt64(42 as UInt) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToInt64(UInt.max - 12) == 4294967283) // For 32-bit systems
#else
assert(JDI.ToInt64(UInt.max - 12) == -13) // For 64-bit systems
#endif
// To Int
assert(JDI.ToInt(42 as Int8) == 42)
assert(JDI.ToInt(-13 as Int8) == -13)
assert(JDI.ToInt(42 as Int32) == 42)
assert(JDI.ToInt(-13 as Int32) == -13)
assert(JDI.ToInt(42 as Int64) == 42)
assert(JDI.ToInt(-13 as Int64) == -13)
assert(JDI.ToInt(42 as Int) == 42)
assert(JDI.ToInt(-13 as Int) == -13)
assert(JDI.ToInt(42 as UInt8) == 42)
assert(JDI.ToInt(0xf3 as UInt8) == 243)
assert(JDI.ToInt(42 as UInt32) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToInt(0xfffffff3 as UInt32) == -13) // For 32-bit systems
#else
assert(JDI.ToInt(0xfffffff3 as UInt32) == 4294967283) // For 64-bit systems
#endif
assert(JDI.ToInt(42 as UInt64) == 42)
assert(JDI.ToInt(UInt64.max - 12) == -13)
assert(JDI.ToInt(42 as UInt) == 42)
assert(JDI.ToInt(UInt.max - 12) == -13)
// To UInt8
assert(JDI.ToUInt8(42 as Int8) == 42)
assert(JDI.ToUInt8(-13 as Int8) == 0xf3)
assert(JDI.ToUInt8(42 as Int32) == 42)
assert(JDI.ToUInt8(-13 as Int32) == 0xf3)
assert(JDI.ToUInt8(42 as Int64) == 42)
assert(JDI.ToUInt8(-13 as Int64) == 0xf3)
assert(JDI.ToUInt8(Int64.max - 12) == 0xf3)
assert(JDI.ToUInt8(42 as Int) == 42)
assert(JDI.ToUInt8(-13 as Int) == 0xf3)
assert(JDI.ToUInt8(Int.max - 12) == 0xf3)
assert(JDI.ToUInt8(42 as UInt8) == 42)
assert(JDI.ToUInt8(0xf3 as UInt8) == 0xf3)
assert(JDI.ToUInt8(42 as UInt32) == 42)
assert(JDI.ToUInt8(0xfffffff3 as UInt32) == 0xf3)
assert(JDI.ToUInt8(42 as UInt64) == 42)
assert(JDI.ToUInt8(UInt64.max - 12) == 0xf3)
assert(JDI.ToUInt8(42 as UInt) == 42)
assert(JDI.ToUInt8(UInt.max - 12) == 0xf3)
// To UInt32
assert(JDI.ToUInt32(42 as Int8) == 42)
assert(JDI.ToUInt32(-13 as Int8) == 0xfffffff3)
assert(JDI.ToUInt32(42 as Int32) == 42)
assert(JDI.ToUInt32(-13 as Int32) == 0xfffffff3)
assert(JDI.ToUInt32(42 as Int64) == 42)
assert(JDI.ToUInt32(-13 as Int64) == 0xfffffff3)
assert(JDI.ToUInt32(Int64.max - 12) == 0xfffffff3)
assert(JDI.ToUInt32(42 as Int) == 42)
assert(JDI.ToUInt32(-13 as Int) == 0xfffffff3)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt32(Int.max - 12) == 0x7ffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt32(Int.max - 12) == 0xfffffff3) // For 64-bit systems
#endif
assert(JDI.ToUInt32(42 as UInt8) == 42)
assert(JDI.ToUInt32(0xf3 as UInt8) == 0xf3)
assert(JDI.ToUInt32(42 as UInt32) == 42)
assert(JDI.ToUInt32(0xfffffff3 as UInt32) == 0xfffffff3)
assert(JDI.ToUInt32(42 as UInt64) == 42)
assert(JDI.ToUInt32(UInt64.max - 12) == 0xfffffff3)
assert(JDI.ToUInt32(42 as UInt) == 42)
assert(JDI.ToUInt32(UInt.max - 12) == 0xfffffff3)
// To UInt64
assert(JDI.ToUInt64(42 as Int8) == 42)
assert(JDI.ToUInt64(-13 as Int8) == 0xfffffffffffffff3)
assert(JDI.ToUInt64(42 as Int32) == 42)
assert(JDI.ToUInt64(-13 as Int32) == 0xfffffffffffffff3)
assert(JDI.ToUInt64(42 as Int64) == 42)
assert(JDI.ToUInt64(-13 as Int64) == 0xfffffffffffffff3)
assert(JDI.ToUInt64(Int64.max - 12) == (UInt64.max >> 1) - 12)
assert(JDI.ToUInt64(42 as Int) == 42)
assert(JDI.ToUInt64(-13 as Int) == 0xfffffffffffffff3)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt64(Int.max - 12) == 0x7ffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt64(Int.max - 12) == 0x7ffffffffffffff3) // For 64-bit systems
#endif
assert(JDI.ToUInt64(42 as UInt8) == 42)
assert(JDI.ToUInt64(0xf3 as UInt8) == 0xf3)
assert(JDI.ToUInt64(42 as UInt32) == 42)
assert(JDI.ToUInt64(0xfffffff3 as UInt32) == 0xfffffff3)
assert(JDI.ToUInt64(42 as UInt64) == 42)
assert(JDI.ToUInt64(UInt64.max - 12) == 0xfffffffffffffff3)
assert(JDI.ToUInt64(42 as UInt) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt64(UInt.max - 12) == 0xfffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt64(UInt.max - 12) == 0xfffffffffffffff3) // For 64-bit systems
#endif
// To UInt
assert(JDI.ToUInt(42 as Int8) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt(-13 as Int8) == 0xfffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt(-13 as Int8) == 0xfffffffffffffff3) // For 64-bit systems
#endif
assert(JDI.ToUInt(42 as Int32) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt(-13 as Int32) == 0xfffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt(-13 as Int32) == 0xfffffffffffffff3) // For 64-bit systems
#endif
assert(JDI.ToUInt(42 as Int64) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt(-13 as Int64) == 0xfffffff3) // For 32-bit systems
assert(JDI.ToUInt(Int64.max - 12) == 0xfffffff3)
#else
assert(JDI.ToUInt(-13 as Int64) == 0xfffffffffffffff3) // For 64-bit systems
assert(JDI.ToUInt(Int64.max - 12) == 0x7ffffffffffffff3)
#endif
assert(JDI.ToUInt(42 as Int) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt(Int.max - 12) == 0x7ffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt(Int.max - 12) == 0x7ffffffffffffff3) // For 64-bit systems
#endif
assert(JDI.ToUInt(42 as UInt8) == 42)
assert(JDI.ToUInt(0xf3 as UInt8) == 0xf3)
assert(JDI.ToUInt(42 as UInt32) == 42)
assert(JDI.ToUInt(0xfffffff3 as UInt32) == 0xfffffff3)
assert(JDI.ToUInt(42 as UInt64) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt(UInt64.max - 12) == 0xfffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt(UInt64.max - 12) == 0xfffffffffffffff3) // For 64-bit systems
#endif
assert(JDI.ToUInt(42 as UInt) == 42)
#if (arch(i386) || arch(arm))
assert(JDI.ToUInt(UInt.max - 12) == 0xfffffff3) // For 32-bit systems
#else
assert(JDI.ToUInt(UInt.max - 12) == 0xfffffffffffffff3) // For 64-bit systems
#endif
print("\nTesting JDI complete.\n")
}
Nếu đây là những phương pháp riêng của bạn, bạn chỉ nên sử dụng 'Int' thay vì' UInt'. Mặc dù các giá trị không bao giờ là tiêu cực, nhưng đề xuất từ tài liệu Swift về cơ bản luôn luôn sử dụng 'Int' trừ khi bạn có lý do cụ thể để làm khác (ví dụ như khả năng tương tác với các hàm C). –
Đây là từ MWPhotoBrowser (ObjectiveC). Tôi đã sử dụng Bridging Headers để cho tôi sử dụng nó nhưng nó hơi kỳ quặc theo cách này. Tôi không có lựa chọn nào khác ngoài việc sử dụng UInt hoặc fork ngoài MWPhotoBrowser và chỉnh sửa nó (khó khăn hơn để duy trì) – Akshat