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;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

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;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163