全特化

对于全特化类的所有参数，都与模板类的所有参数一一对应。
如下：
int 对应 T1，double 对应T2


#include<iostream>
using namespace std;

//模板类
template <class T1,class T2>
class base
{
public:
	void f(T1 a, T2 b)
	{
		cout << "模板类：";
		cout << a << " " << b << endl;
	}
};

//全特化类		int 对应 T1，double 对应T2
template<>
class base<int,double>
{
public:
	void f(int a, double b)
	{
		cout << "全特化类：";
		cout << a << " " << b << endl;
	}
};

int main()
{
	base<int,int> b1;
	cout << "1:" << endl;
	b1.f(1, 2);

	base<int,double> b2;
	cout << "2:" << endl;
	b2.f(1, 2.3);

	base<char, double> b3;
	cout << "3:" << endl;
	b3.f('a', 2.0);
}

输出:
1:
模板类：1 2
2:
全特化类：1 2.3
3:
模板类：a 2

可见，当满足全特化类时，优先调用全特化类，否则调用模板类

优先级：全特化类>模板类

偏特化类

偏特化类位于全特化类和模板类之间，只对模板类的部分参数进行显示声明
如下：
T1 无对应，默认为模板参数
T2对应double

#include<iostream>
using namespace std;

//模板类
template <class T1,class T2>
class base
{
public:
	void f(T1 a, T2 b)
	{
		cout << "模板类：";
		cout << a << " " << b << endl;
	}
};


//偏特化类
template<class T>
class base<T,double>
{
public:
	void f(T a, double b)
	{
		cout << "偏特化类：";
		cout << a << " " << b << endl;
	}
};

int main()
{
	base<int,int> b1;
	cout << "1:" << endl;
	b1.f(1, 2);

	base<int,double> b2;
	cout << "2:" << endl;
	b2.f(1, 2.3);

	base<char, double> b3;
	cout << "3:" << endl;
	b3.f('a', 2.0);
}

输出：
1:
模板类：1 2
2:
偏特化类：1 2.3
3:
偏特化类：a 2

可见，当满足偏特化类时，优先调用偏特化类，否则调用模板类

优先级：偏特化类>模板类

全特化类与偏特化类优先级

#include<iostream>
using namespace std;

//模板类
template <class T1,class T2>
class base
{
public:
	void f(T1 a, T2 b)
	{
		cout << "模板类：";
		cout << a << " " << b << endl;
	}
};

//全特化类
template<>
class base<int,double>
{
public:
	void f(int a, double b)  
	{
		cout << "全特化类：";
		cout << a << " " << b << endl;
	}
};

//偏特化类
template<class T>
class base<T,double>
{
public:
	void f(T a, double b)
	{
		cout << "偏特化类：";
		cout << a << " " << b << endl;
	}
};

int main()
{
	base<int,int> b1;
	cout << "1:" << endl;
	b1.f(1, 2);

	base<int,double> b2;
	cout << "2:" << endl;
	b2.f(1, 2.3);

	base<char, double> b3;
	cout << "3:" << endl;
	b3.f('a', 2.0);
}

输出：
1:
模板类：1 2
2:
全特化类：1 2.3
3:
偏特化类：a 2

对于模板类和全特化类、偏特化类共同存在时：