繼前天湊動態多維數組失敗后，經指導，終于將其實現。

把數組的維度一并放在模板里，而不用構造函數來實現，于是定義Array看起來像下邊這樣，其中NewArray是一個全局變量：

operator[] 是利用特化類模板來實現的：

template<typename _Type, int _DimensionCount>
class Array
{
private:
  _Type* Elements;
  int Size;
public:
  Array<_Type, DimensionCount-1> operator[](const int Index);
};

template<typename _Type>
class Array<_Type, 1>
{
private:
  _Type* Elements;
  int Size;
public:
  _Type& operator[](const int Index);
  _Type operator[](const int Index)const;
};

在實現 Array<_Type, DimensionCount-1> operator[](const int Index) 時遇到一個問題，我需要返回一個Array<_Type, DimensionCount-1>，這個結果是根據當前的Array的信息來生成的，肯定需要用到private成員Elements，于是考慮用friend class Array<_Type, DimensionCount-1>，沒想到編譯器又噴我了，還是不能通過，原因不明T_T，無奈只能把Elements這些信息放到public下。

Array的測試用例如下：

#include "Library/UnitTest/UnitTest.h"
#include "Library/Basic/Array.h"

using namespace Lyt;

void InitArray(int* a, const int Size)
{
    if (a)
    {
        for (int i=0; i<=Size-1; i++) a[i]=i;
    }
}

bool CheckArray(int* a1, int* a2, const int Size)
{
    if (a1 && a2)
    {
        for (int i=0; i<=Size-1; i++)
            if (a1[i]!=a2[i]) return false;
    }
    else if (a1 || a2) return false;
    return true;
}

TESTCASE(ArrayConstructorAssign, "ArrayConstructor")
{
    int a[30];
    InitArray(a, 30);
    int dims[3];
    dims[0]=2;
    dims[1]=3;
    dims[2]=5;

    Array<int, 3> a1;
    EXPECT_TRUE(a1.Dimensions!=0, "DefaultConstructor");
    Array<int, 3> a2=NewArray[2][3][5];
    InitArray(a2.Elements, a2.Size);
    EXPECT_TRUE(CheckArray(dims, a2.Dimensions, 3) && CheckArray(a, a2.Elements, a2.Size), "NewArrayConstructor");
    Array<int, 3> a3=a2;
    EXPECT_TRUE(CheckArray(dims, a3.Dimensions, 3) && CheckArray(a, a3.Elements, a3.Size), "CopyConstructor");
    Array<int, 2> a4=a3[1];
    EXPECT_TRUE(CheckArray(dims+1, a4.Dimensions, 2) && CheckArray(a+15, a4.Elements, a4.Size), "CopyConstructor operator[]");
    Array<int, 1> a5=a3[1][1];
    EXPECT_TRUE(CheckArray(dims+2, a5.Dimensions, 1) && CheckArray(a+20, a5.Elements, a5.Size), "CopyConstructor operator[]");
    Array<int, 1> a6=a5;
    EXPECT_TRUE(CheckArray(dims+2, a6.Dimensions, 1) && CheckArray(a+20, a6.Elements, a6.Size), "CopyConstructor");

    EXPECT_TRUE(a2[1][1][0]==20, "operator[]");
    EXPECT_TRUE((a2[1][1][0]=30)==30, "operator=");
}

TESTCASE(ArrayAssign, "Array::operator=")
{
    int a1[30];
    InitArray(a1, 30);
    int dims1[3];
    dims1[0]=2;
    dims1[1]=3;
    dims1[2]=5;

    int a2[8];
    InitArray(a2, 8);
    int dims2[3];
    dims2[0]=2;
    dims2[1]=2;
    dims2[2]=2;

    Array<int, 3> Array1=NewArray[2][3][5];
    InitArray(Array1.Elements, Array1.Size);
    Array<int, 3> Array2=Array1;

    Array<int, 3> Array3=NewArray[2][2][2];
    InitArray(Array3.Elements, Array3.Size);
    Array1=Array3;
    EXPECT_TRUE(CheckArray(dims2, Array1.Dimensions, 3) && CheckArray(a2, Array1.Elements, Array1.Size), "operator=");
    EXPECT_TRUE(Array1[0][1][1]==3, "operator[]");

    Array<int, 2> Array4=Array1[0];
    Array<int, 1> Array5=Array1[0][1];
    Array5[1]=9;
    EXPECT_TRUE(Array1[0][1][1]==9 && Array3[0][1][1]==9 && Array4[1][1]==9, "operator=");

    Array3=Array2;
    EXPECT_TRUE(CheckArray(dims1, Array3.Dimensions, 3) && CheckArray(a1, Array3.Elements, Array3.Size), "operator=");
}

TESTCASE(ArrayClone, "Array::Clone")
{
    int a[30];
    InitArray(a, 30);
    int dims[3];
    dims[0]=2;
    dims[1]=3;
    dims[2]=5;

    Array<int, 3> a1=NewArray[2][3][5];
    InitArray(a1.Elements, a1.Size);
    Array<int, 3> a2=a1.Clone();
    EXPECT_TRUE(CheckArray(dims, a2.Dimensions, 3) && CheckArray(a, a2.Elements, a2.Size), "Clone");
    a1[0][0][0]=100;
    EXPECT_TRUE(a1[0][0][0]==100 && a2[0][0][0]==0, "operator=");
}

Array源碼：

#ifndef ARRAY_H
#define ARRAY_H

#include <memory.h>

namespace Lyt
{
    template<int _DimensionCount>
    class ArrayDimension
    {
    public:
        int Data[_DimensionCount+1];

        ArrayDimension()
        {
            for (int i=0; i<=_DimensionCount-1; i++) Data[i]=0;
        }

        ArrayDimension(const int Dimension, int* PrevDimensions)
        {
            Data[_DimensionCount-1]=Dimension;
            memcpy(Data, PrevDimensions, sizeof(int)*(_DimensionCount-1));
        }

        ArrayDimension<_DimensionCount+1> operator[](const int Dimension)
        {
            return ArrayDimension<_DimensionCount+1>(Dimension, Data);
        }

        int GetSize()const
        {
            int Result=1;
            for (int i=0; i<=_DimensionCount-1; i++) Result*=Data[i];
            return Result;
        }
    };

    extern ArrayDimension<0> NewArray; 

    template<typename _Type, int _DimensionCount>
    class Array
    {
    protected:
        void RefIncrease()
        {
            if (RefCount) (*RefCount)++;
        }

        void RefDecrease()
        {
            if (RefCount)
            {
                if (--(*RefCount)==0)
                {
                    delete RefCount;
                    delete[] (Dimensions-DimensionsIndex);
                    if (Elements) delete[] (Elements-ElementsIndex);
                    RefCount=0;
                    Dimensions=0;
                    Elements=0;
                    Size=0;
                    ElementsIndex=0;
                    DimensionsIndex=0;
                }
            }
        }
    
    public:
        int* RefCount;
        int* Dimensions;
        _Type* Elements;
        int Size;
        int ElementsIndex;
        int DimensionsIndex;

        Array()
        {
            RefCount=new int(1);
            Dimensions=new int[_DimensionCount];
            Elements=0;
            Size=0;
            ElementsIndex=0;
            DimensionsIndex=0;
        }

        Array(const Array<_Type, _DimensionCount>& Object)
        {
            RefCount=Object.RefCount;
            Dimensions=Object.Dimensions;
            Elements=Object.Elements;
            Size=Object.Size;
            ElementsIndex=Object.ElementsIndex;
            DimensionsIndex=Object.DimensionsIndex;
            RefIncrease();
        }

        Array(const ArrayDimension<_DimensionCount> Dims)
        {
            RefCount=new int(1);
            Dimensions=new int[_DimensionCount];
            memcpy(Dimensions, Dims.Data, sizeof(int)*_DimensionCount);
            Size=Dims.GetSize();
            Elements=new _Type[Size];
            ElementsIndex=0;
            DimensionsIndex=0;
        }

        ~Array()
        {
            RefDecrease();
        }

        Array<_Type, _DimensionCount>& operator=(const Array<_Type, _DimensionCount>& Object)
        {
            RefDecrease();
            RefCount=Object.RefCount;
            Dimensions=Object.Dimensions;
            Elements=Object.Elements;
            Size=Object.Size;
            ElementsIndex=Object.ElementsIndex;
            DimensionsIndex=Object.DimensionsIndex;
            RefIncrease();
            return *this;
        }

        Array<_Type, _DimensionCount-1> operator[](const int Index)
        {
            RefIncrease();
            Array<_Type, _DimensionCount-1> Result;
            delete Result.RefCount;
            Result.RefCount=RefCount;
            Result.Size=Size/Dimensions[0];
            Result.Dimensions=Dimensions+1;
            Result.Elements=Elements+Index*Result.Size;
            Result.ElementsIndex=ElementsIndex+Index*Result.Size;
            Result.DimensionsIndex=DimensionsIndex+1;
            return Result;
        }

        Array<_Type, _DimensionCount> Clone()const
        {
            Array<_Type, _DimensionCount> Result;
            memcpy(Result.Dimensions, Dimensions, sizeof(int)*(_DimensionCount));
            Result.Size=Size;
            Result.Elements=new _Type[Size];
            memcpy(Result.Elements, Elements, sizeof(int)*(Size));
            return Result;
        }
    };

    template<typename _Type>
    class Array<_Type, 1>
    {
    protected:
        void RefIncrease()
        {
            if (RefCount) (*RefCount)++;
        }

        void RefDecrease()
        {
            if (RefCount)
            {
                if (--(*RefCount)==0)
                {
                    delete RefCount;
                    delete[] (Dimensions-DimensionsIndex);
                    if (Elements) delete[] (Elements-ElementsIndex);
                    RefCount=0;
                    Dimensions=0;
                    Elements=0;
                    Size=0;
                    ElementsIndex=0;
                    DimensionsIndex=0;
                }
            }
        }
    
    public:
        int* RefCount;
        int* Dimensions;
        _Type* Elements;
        int Size;
        int ElementsIndex;
        int DimensionsIndex;

        Array()
        {
            RefCount=new int(1);
            Dimensions=new int[1];
            Elements=0;
            Size=0;
            ElementsIndex=0;
            DimensionsIndex=0;
        }

        Array(const Array<_Type, 1>& Object)
        {
            RefCount=Object.RefCount;
            Dimensions=Object.Dimensions;
            Elements=Object.Elements;
            Size=Object.Size;
            ElementsIndex=Object.ElementsIndex;
            DimensionsIndex=Object.DimensionsIndex;
            RefIncrease();
        }

        Array(const ArrayDimension<1> Dims)
        {
            RefCount=new int(1);
            Dimensions=new int[];
            memcpy(Dimensions, Dims.Data, sizeof(int));
            Size=Dims.GetSize();
            Elements=new _Type[Size];
            ElementsIndex=0;
            DimensionsIndex=0;
        }

        ~Array()
        {
            RefDecrease();
        }

        Array<_Type, 1>& operator=(const Array<_Type, 1>& Object)
        {
            RefDecrease();
            RefCount=Object.RefCount;
            Dimensions=Object.Dimensions;
            Elements=Object.Elements;
            Size=Object.Size;
            ElementsIndex=Object.ElementsIndex;
            DimensionsIndex=Object.DimensionsIndex;
            RefIncrease();
            return *this;
        }

        _Type& operator[](const int Index)
        {
            if (Index<0 || Index>=Dimensions[0]) throw L"越界訪問";
            else return Elements[Index];
        }

        _Type operator[](const int Index)const
        {
            if (Index<0 || Index>=Dimensions[0]) throw L"越界訪問";
            else return Elements[Index];
        }

        Array<_Type, 1> Clone()const
        {
            Array<_Type, 1> Result;
            mencpy(Result.Dimensions, Dimensions, sizeof(int));
            Result.Size=Size;
            Result.Elements=new _Type[Size];
            memcpy(Result.Elements, Elements, sizeof(int)*(Size));
            return Result;
        }
    };
}

#endif