練手之用STL類型區分應用

#include  <iostream>
using namespace std;
//一些模板練手時的小應用辨別基本類型和自訂類型
//使用方法就是便舉有限的基本類型，無他
//基本類模板枚舉非基本類型
template < typename T>
class IsFoundationType
{
public:
 enum{ Yes = 0, No = 1 };
};
//宏定義MACRO_FOUNDATION_TYPE(T)特化依次調用特化所有
//基礎資料型別 (Elementary Data Type)枚舉為Yes = 1
#define MACRO_FOUNDATION_TYPE(T)  /
template<> class IsFoundationType<T> /
{        /
public:       /
 enum{ Yes = 1, No = 0 }; /
};        /
//使用宏進行特化以便得到最特殊的執行個體點
MACRO_FOUNDATION_TYPE(void)
MACRO_FOUNDATION_TYPE(bool)
MACRO_FOUNDATION_TYPE(char)
MACRO_FOUNDATION_TYPE(unsigned char)
MACRO_FOUNDATION_TYPE(wchar_t)
MACRO_FOUNDATION_TYPE(short)
MACRO_FOUNDATION_TYPE(signed int)
MACRO_FOUNDATION_TYPE(unsigned int)
MACRO_FOUNDATION_TYPE(signed long)
MACRO_FOUNDATION_TYPE(unsigned long)

#if LONGLONG_EXISTS
 MACRO_FOUNDATION_TYPE(signed long long)
 MACRO_FOUNDATION_TYPE(unsigned long long )
#endif

MACRO_FOUNDATION_TYPE(double)
MACRO_FOUNDATION_TYPE(float)
MACRO_FOUNDATION_TYPE(long double)

//測試的函數模板，可以看看非常簡單但是這種思想
//還是比較有用，窮舉有限數目匹配。
template <typename T>
void test( T const& t )
{
     if( IsFoundationType<T>::Yes )
     {
          cout<<"T is fundamental type"<<endl;
     }
     else
     {
          cout<<"T isn't fundamental type"<<endl;
     }
     if( IsDouble<T>::Yes )
     {
          cout<<"T is double type"<<endl;
     }
     else
     {
          cout<<"T isn't double type"<<endl;
     }
}