模版小结2

// test2.cpp : 定义控制台应用程序的入口点。
//


#include "stdafx.h"
#include <string>
#include <vector>
#include <iostream>


template<class T, T v>
struct integral_constant {
  static const T value = v;
  typedef T value_type;
  typedef integral_constant<T, v> type;
};


template <class T, T v> const T integral_constant<T, v>::value;


typedef integral_constant<bool, true> true_type;
typedef integral_constant<bool, false> false_type;


template<class> struct is_array : public false_type {};
template<class T, size_t n> struct is_array<T[n]> : public true_type {};
template<class T> struct is_array<T[]> : public true_type {};




template<class T>
class CT;


template<class T>
class CT<T[]>
{
public:
CT(T* t):_t(t)
{
std::cout << "CT<T[]>" << std::endl;
}


T operator[](int n)
{
return _t[n];
}


T* _t;
};


template<class T, int n>
class CT<T[n]>
{
public:
CT(T* t):_t(t)
{
std::cout << "CT<T[n]>" << std::endl;
}


T operator[](int n)
{
return _t[n];
}


T* _t;
};


int _tmain(int argc, _TCHAR* argv[])
{
bool bArray = is_array<int[]>::value;
bArray = is_array<int[3]>::value;


int ar[10] = {1, 2, 4, 5, 6 , 6,6, 9};
CT<int[]> t(&ar[0]);


for(int i = 0; i < 10; i++)
{
std::cout << t[i] << " ";
}


std::cout << std::endl;


CT<int[12]> t2(&ar[0]);


for(int i = 0; i < 10; i++)
{
std::cout << t2[i] << " ";
}


return 0;
}