C#:数字的通用接口(interface)

Question

我正在尝试执行一些独立于数字类型的通用数字操作。但是，我不知道如何使用泛型来做到这一点。第一个想法是使用 where 语句过滤传入类型，但所有数字类型都是封闭的，因此对于通用过滤器无效。此外，泛型不允许标准数字运算(加法、移位等)，因此我能想到的唯一解决方案是非泛型地重写每个方法。还有其他想法吗？

作为引用，以下是我最初尝试的代码:

    private const int BYTE_SIZE = 8;

    private const int UINT16_SIZE = 16;

    private const int UINT32_SIZE = 32;

    private const int UINT64_SIZE = 64;

    public static byte[] ToBytes(UInt16[] pnaValues)
    {
        return ToSmaller<byte, UInt16>(pnaValues, BYTE_SIZE, UINT16_SIZE);
    }

    public static byte[] ToBytes(UInt32[] pnaValues)
    {
        return ToSmaller<byte, UInt32>(pnaValues, BYTE_SIZE, UINT32_SIZE);
    }

    ....

    public static UInt16[] ToUInt16s(byte[] pnaValues)
    {
        return ToLarger<UInt16, byte>(pnaValues, UINT16_SIZE, BYTE_SIZE);
    }

    public static UInt16[] ToUInt16s(UInt32[] pnaValues)
    {
        return ToSmaller<UInt16, UInt32>(pnaValues, UINT16_SIZE, UINT32_SIZE);
    }

    ...

    public static UInt64[] ToUInt64s(UInt32[] pnaValues)
    {
        return ToLarger<UInt64, UInt32>(pnaValues, UINT64_SIZE, UINT32_SIZE);
    }

    private static TLarger[] ToLarger<TLarger, TSmaller>(TSmaller[] pnaSmaller, int pnLargerSize, int pnSmallerSize)
        where TLarger : byte, UInt16, UInt32, UInt64
        where TSmaller : byte, UInt16, UInt32, UInt64
    {
        TLarger[] lnaRetVal = null;
        int lnSmallerPerLarger = pnLargerSize / pnSmallerSize;

        System.Diagnostics.Debug.Assert((pnLargerSize % pnSmallerSize) == 0);

        if (pnaSmaller != null)
        {
            System.Diagnostics.Debug.Assert((pnaSmaller % lnSmallerPerLarger) == 0);

            lnaRetVal = new TLarger[pnaSmaller.Length / lnSmallerPerLarger];

            for (int i = 0; i < lnaRetVal.Length; i++)
            {
                lnaRetVal[i] = 0;

                for (int j = 0; j < lnSmallerPerLarger; j++)
                {
                    lnaRetVal[i] = (lnaRetVal[i] << pnLargerSize) + pnaSmaller[i * lnSmallerPerLarger + j];
                }
            }
        }

        return lnaRetVal;
    }

    private static TSmaller[] ToSmaller<TSmaller, TLarger>(TLarger[] pnaLarger, int pnSmallerSize, int pnLargerSize)
        where TSmaller : byte, UInt16, UInt32, UInt64
        where TLarger : byte, UInt16, UInt32, UInt64
    {
        TSmaller[] lnaRetVal = null;
        int lnSmallerPerLarger = pnLargerSize / pnSmallerSize;

        System.Diagnostics.Debug.Assert((pnLargerSize % pnSmallerSize) == 0);

        if (pnaSmaller != null)
        {
            lnaRetVal = new TSmaller[pnaLarger.Length * lnSmallerPerLarger];

            for (int i = 0; i < lnaRetVal.Length; i++)
            {
                for (int j = 0; j < lnSmallerPerLarger; j++)
                {
                    lnaRetVal[i * lnSmallerPerLarger + (lnSmallerPerLarger - 1 - j)]
                        = pnaLarger[i] >> (j * pnLargerSize);
                }
            }
        }

        return lnaRetVal;
    }

Answer 1

数字类型实现的算术运算没有通用接口(interface)。 Generic operators可能有助于解决您的问题。