模板特化 用法

函数模板特化 用法

#include 
using namespace std;

template <typename T>
bool Less(T x, T y)
{
	return x < y;
}

template <>
bool Less<int*>(int* p1, int* p2)
{
	return *p1 < *p2;
}

int main()
{
	int number1 = 10;
	int number2 = 20;
	cout << Less(number1, number2) << endl;
	//
	double number3 = 2.7;
	double number4 = 1.99;
	cout << Less(number3, number4) << endl;
	//
	int number5 = 10;
	int number6 = 100;
	cout << Less(&number5, &number6) << endl;
	return 0;
}

类模板特化 用法

#include 
using namespace std;

template <typename T1, typename T2>
class TwoObjs
{
public:
	TwoObjs(T1 x, T2 y)
		:_obj1(x)
		,_obj2(y)
	{
		cout << "实例化对象里有两个成员，我要比较他们咯：" << endl;
	}
	void LessCompare()
	{
		cout << "第一个成员:" << _obj1 << endl;
		cout << "第二个成员:" << _obj2 << endl;
		cout << "比较结果:";
		cout << (_obj1 < _obj2) << endl << endl;;
	}
private:
	T1 _obj1;
	T2 _obj2;
};

//全特化
template <>
class TwoObjs<int, char>
{
public:
	TwoObjs(int x, char y)
		:_obj1(x)
		, _obj2(y)
	{
		cout << "实例化对象里有两个成员，我要比较他们咯：" << endl;
	}
	void LessCompare()
	{
		cout << "第一个成员:" << _obj1 << endl;
		cout << "第二个成员:" << _obj2 << endl;
		cout << "说实话，不想比较，整数与字符比较太欺负人了" << endl;
	}
private:
	int _obj1;
	char _obj2;
};
template <>
class TwoObjs<char, int>
{
public:
	TwoObjs(char x, int y)
		:_obj1(x)
		, _obj2(y)
	{
		cout << "实例化对象里有两个成员，我要比较他们咯：" << endl;
	}
	void LessCompare()
	{
		cout << "第一个成员:" << _obj1 << endl;
		cout << "第二个成员:" << _obj2 << endl;
		cout << "说实话，不想比较，整数与字符比较太欺负人了" << endl;
	}
private:
	char _obj1;
	int _obj2;
};

//偏特化
template <typename T1, typename T2>
class TwoObjs<T1* , T2*>
{
public:
	TwoObjs(T1* x, T2* y)
		:_obj1(x)
		,_obj2(y)
	{}
	void LessCompare()
	{
		cout << "第一个成员（指针）:" << _obj1 << endl;
		cout << "第二个成员（指针）:" << _obj2 << endl;
		cout << "分别解引用:" << endl;
		cout << "第一个指针解引用出来:" << *_obj1 << endl;
		cout << "第二个指针解引用出来:" << *_obj2 << endl;
		cout << "比较结果:";
		cout << (*_obj1 < *_obj2) << endl << endl;;
	}
private:
	T1* _obj1;
	T2* _obj2;
};
template <typename T1, typename T2>
class TwoObjs<T1&, T2&>
{
public:
	TwoObjs(T1& x, T2& y)
		:_obj1(x)
		, _obj2(y)
	{}
	void LessCompare()
	{
		cout << "第一个成员（引用）:" << _obj1 << endl;
		cout << "第二个成员（引用）:" << _obj2 << endl;
		cout << "比较结果:";
		cout << (_obj1 < _obj2) << endl << endl;;
	}
private:
	T1& _obj1;
	T2& _obj2;
};
template <typename T>
class TwoObjs<T, size_t>
{
public:
	TwoObjs(T x, size_t y)
		:_obj1(x)
		, _obj2(y)
	{}
	void LessCompare()
	{
		cout << "第二个成员是无符号整形噢" << endl;
		cout << "第一个成员:" << _obj1 << endl;
		cout << "第二个成员:" << _obj2 << endl;
		cout << "比较结果:";
		cout << (_obj1 < _obj2) << endl << endl;;
	}
private:
	T _obj1;
	size_t _obj2;
};


int main()
{
	TwoObjs<int, int> a1(1, 2);
	a1.LessCompare();

	TwoObjs<double, double> a2(2.1, 1.9);
	a2.LessCompare();

	TwoObjs<int, char> a3(1, 'L');
	a3.LessCompare();
	cout << endl;

	TwoObjs<char, int> a4('D', 10);
	a4.LessCompare();
	cout << endl;

	int number1 = 10;
	int number2 = 20;
	TwoObjs<int*, int*> a5(&number1,&number2);
	a5.LessCompare();

	int number3 = 99;
	double number4 = 89.99;
	TwoObjs<int&, double&> a6(number3, number4);
	a6.LessCompare();

	int number5 = -1;
	size_t number6 = 1;
	TwoObjs<int,size_t> a7(number5, number6);
	a7.LessCompare();
	return 0;
}