类模板

实现一个三维数组模版CArray3D，可以用来生成元素为任意类型变量的三维数组

1.用一个模板实现：

#include <iostream>using namespace std;template <class T>class CArray3D{template <class T>class CArray2D{template <class T>class CArray1D {public:CArray1D() :p(NULL){}void set(T a){p = new T[a];_a = a;}inline T& operator[](long elem) const{//  assert( elem >= 0 && elem < _a );   return p[elem];}~CArray1D(){delete[] p;};private:T* p;T _a;};public:CArray2D() :p(NULL){}void set(T a, T b){p = new CArray1D<T>[a];for (int i = 0; i<a; i++){p[i].set(b);}_b = b;}inline CArray1D<T>& operator[](long elem) const{//  assert( elem >= 0 && elem < _b );   return p[elem];}~CArray2D(){delete[] p;}private:CArray1D<T>* p;T _b;};public:CArray3D(T a, T b, T c){p = new CArray2D<T>[a];for (int i = 0; i<a; i++){p[i].set(b, c);}_c = c;}inline CArray2D<T>& operator[](long elem) const{//  assert( elem >= 0 && elem < _c );   return p[elem];}~CArray3D(){delete[] p;}private:CArray2D<T>* p;T _c;};int main(){CArray3D<int> a(3, 4, 5);int No = 0;for (int i = 0; i < 3; ++i)for (int j = 0; j < 4; ++j)for (int k = 0; k < 5; ++k)a[i][j][k] = No++;for (int i = 0; i < 3; ++i)for (int j = 0; j < 4; ++j)for (int k = 0; k < 5; ++k)cout << a[i][j][k] << ",";return 0;}

2.多个模板实现：

#include <iostream>using namespace std;template <class T>class CArray1D {public:CArray1D() :p(NULL){}void set(T a){p = new T[a];_a = a;}inline T& operator[](long elem) const{//  assert( elem >= 0 && elem < _a );return p[elem];}~CArray1D(){delete[] p;}private:T* p;T _a;};    template <class T>class CArray2D{public:CArray2D() :p(NULL){}void set(T a, T b){p = new CArray1D<T>[a];for (int i = 0; i<a; i++){p[i].set(b);}_b = b;}inline CArray1D<T>& operator[](long elem) const{//  assert( elem >= 0 && elem < _b );return p[elem];}~CArray2D(){delete[] p;}private:CArray1D<T>* p;T _b;};template <class T>class CArray3D{public:CArray3D(T a, T b, T c){p = new CArray2D<T>[a];for (int i = 0; i<a; i++){p[i].set(b, c);}_c = c;}inline CArray2D<T>& operator[](long elem) const{//  assert( elem >= 0 && elem < _c );return p[elem];}~CArray3D(){delete[] p;}private:CArray2D<T>* p;T _c;};int main(){CArray3D<int> a(3, 4, 5);int No = 0;for (int i = 0; i < 3; ++i)for (int j = 0; j < 4; ++j)for (int k = 0; k < 5; ++k)a[i][j][k] = No++;for (int i = 0; i < 3; ++i)for (int j = 0; j < 4; ++j)for (int k = 0; k < 5; ++k)cout << a[i][j][k] << ",";return 0;}