const char*和const char[]怎么识别？

#include <iostream>
using namespace std;

template<typename T> class _ischararray_;

template<typename T, int N> class _ischararray_<T[N]> 
{ 
public: static bool _ischararray(){return true;}
};  

template<typename T>  class _ischararray_<T*> 
{ 
public: static bool _ischararray(){return false;}
};

template<class T>  bool isCharArray(const T& x) 
{ 
	return _ischararray_<T>::_ischararray();
}

int _tmain(int argc, _TCHAR* argv[])
{
	const char* s1   = "12345";  
	const char  s2[] = "12345";
	isCharArray("12345")?cout<<"char []"<<endl:cout<<"char*"<<endl;  //char []
	isCharArray(s1)?cout<<"char []"<<endl:cout<<"char*"<<endl;  //char *
	isCharArray(s2)?cout<<"char []"<<endl:cout<<"char*"<<endl; //char []

	return 0;
}

或者下面这段我没有看懂的代码，麻烦大牛们帮忙解释一下下面的代码段：

#include <iostream>
using namespace std;

namespace X
{
	template<typename T, unsigned int SIZE>
	bool IsArray (T (&a)[SIZE]) { return true; }

	template<typename T>
	bool IsArray (const T *&p) { return false; }
}

namespace Y
{
	typedef char (&yes)[2];

	template<typename T, unsigned int SIZE>
	yes IsArray (T (&a)[SIZE]);

	template<typename T>
	char IsArray (const T *&p);
}

int _tmain(int argc, _TCHAR* argv[])
{
	char s1[]  = "hello";
	const char *s2   = "hello";
#if 1
	using namespace X;
	if(true == IsArray(s2))
		throw 0;
	if(false == IsArray("12345"))
		throw 0;
	if(false == IsArray(s1))
		throw 0;
#else
	// 编译期间解决该问题
	using namespace Y;
	if(sizeof(IsArray(s2)) == sizeof(yes))
		throw 0;
	if(sizeof(IsArray(s1)) != sizeof(yes))
		throw 0;
#endif

	return 0;
}