1 #ifndef TEMPLATE_DEMO_HXX
 2 #define TEMPLATE_DEMO_HXX
 3
 4 template<class T> class A{
 5     public:
 6         T g(T a,T b);
 7         A();
 8 };
 9
10 #endif

 1 #include<iostream.h>
 2 #include "TemplateDemo.h"
 3
 4 template<class T> A<T>::A(){}
 5
 6 template<class T> T A<T>::g(T a,T b){
 7     return a+b;
 8 }
 9
10 void main(){
11     A<int> a;
12     cout<<a.g(2,3.2)<<endl;
13 }

1 --------------------Configuration: TemplateDemo - Win32 Debug--------------------
2 Compiling...
3 TemplateDemo.cpp
4 G:\C++\CDaima\TemplateDemo\TemplateDemo.cpp(12) : warning C4244: 'argument' : conversion from 'const double' to 'int', possible loss of data
5
6 TemplateDemo.obj - 0 error(s), 1 warning(s)

 1 #ifndef TEMPLATE_DEMO_HXX
 2 #define TEMPLATE_DEMO_HXX
 3
 4 template<class T,int MAXSIZE> class Stack{//MAXSIZE由用户创建对象时自行设置
 5     private:
 6         T elems[MAXSIZE];    // 包含元素的数组
 7         int numElems;    // 元素的当前总个数
 8     public:
 9         Stack();    //构造函数
10         void push(T const&);    //压入元素
11         void pop();        //弹出元素
12         T top() const;    //返回栈顶元素
13         bool empty() const{     // 返回栈是否为空
14             return numElems == 0;
15         }
16         bool full() const{    // 返回栈是否已满
17             return numElems == MAXSIZE;
18         }
19 };
20
21 template <class T,int MAXSIZE>
22 Stack<T,MAXSIZE>::Stack():numElems(0){     // 初始时栈不含元素
23     // 不做任何事情
24 }
25
26 template <class T,int MAXSIZE>
27 void Stack<T, MAXSIZE>::push(T const& elem){
28     if(numElems == MAXSIZE){
29         throw std::out_of_range("Stack<>::push(): stack is full");
30     }
31     elems[numElems] = elem;   // 附加元素
32     ++numElems;               // 增加元素的个数
33 }
34
35 template<class T,int MAXSIZE>
36 void Stack<T,MAXSIZE>::pop(){
37     if (numElems <= 0) {
38         throw std::out_of_range("Stack<>::pop(): empty stack");
39     }
40     --numElems;               // 减少元素的个数
41 }
42
43 template <class T,int MAXSIZE>
44 T Stack<T,MAXSIZE>::top()const{
45     if (numElems <= 0) {
46         throw std::out_of_range("Stack<>::top(): empty stack");
47     }
48     return elems[numElems-1];  // 返回最后一个元素
49 }
50
51 #endif

 1 #include<iostream.h>
 2 #include <iostream>
 3 #include <string>
 4 #include <cstdlib>
 5 #include "TemplateDemo.h"
 6
 7 int main(){
 8     try {
 9         Stack<int,20>  int20Stack;  // 可以存储20个int元素的栈
10         Stack<int,40>  int40Stack;  // 可以存储40个int元素的栈
11         Stack<std::string,40> stringStack; // 可存储40个string元素的栈
12
13         // 使用可存储20个int元素的栈
14         int20Stack.push(7);
15         std::cout << int20Stack.top() << std::endl;    //7
16         int20Stack.pop();
17
18         // 使用可存储40个string的栈
19         stringStack.push("hello");
20         std::cout << stringStack.top() << std::endl;    //hello
21         stringStack.pop();
22         stringStack.pop();    //Exception: Stack<>::pop<>: empty stack
23         return 0;
24     }
25     catch (std::exception const& ex) {
26         std::cerr << "Exception: " << ex.what() << std::endl;
27         return EXIT_FAILURE;  // 退出程序且有ERROR标记
28     }
29 }

 1 #ifndef TEMPLATE_DEMO_O1
 2 #define TEMPLATE_DEMO_01
 3
 4 template<typename T> class CompareDemo{
 5     public:
 6         int compare(const T&, const T&);
 7 };
 8
 9 template<typename T>
10 int CompareDemo<T>::compare(const T& a,const T& b){
11     if((a-b)>0)
12         return 1;
13     else if((a-b)<0)
14         return -1;
15     else
16         return 0;
17 }
18
19 #endif

1 #include<iostream.h>
2 #include "TemplateDemo01.h"
3
4 void main(){
5     CompareDemo<int> cd;
6     cout<<cd.compare(2,3)<<endl;
7 }

1 #include<iostream.h>
2 #include "TemplateDemo01.h"
3
4 void main(){
5     CompareDemo<double> cd;
6     cout<<cd.compare(3.2,3.1)<<endl;
7 }

 1 #ifndef TEMPLATE_DEMO_O1
 2 #define TEMPLATE_DEMO_01
 3
 4 template<typename T> class CompareDemo{
 5     public:
 6         int compare(T&, T&);
 7 };
 8
 9 template<typename T>
10 int CompareDemo<T>::compare(T& a,T& b){
11     if((a-b)>0)
12         return 1;
13     else if((a-b)<0)
14         return -1;
15     else
16         return 0;
17 }
18
19 #endif

1 #include<iostream.h>
2 #include "TemplateDemo01.h"
3
4 void main(){
5     CompareDemo<int> cd;
6     int a=2,b=3;
7     cout<<cd.compare(a,b)<<endl;
8 }

 1 #include<iostream.h>
 2
 3 template<typename T>
 4 const T& max(const T& a,const T& b){
 5     return a>b ? a:b;
 6 }
 7
 8 void main(){
 9     cout<<max(2.1,2.2)<<endl;//模板实参被隐式推演成double
10     cout<<max<double>(2.1,2.2)<<endl;//显示指定模板参数。
11     cout<<max<int>(2.1,2.2)<<endl;//显示指定的模板参数，会将函数函数直接转换为int。
12 }

1 --------------------Configuration: TemplateDemo02 - Win32 Debug--------------------
2 Compiling...
3 TemplateDemo02.cpp
4 G:\C++\CDaima\TemplateDemo02\TemplateDemo02.cpp(11) : 　　warning C4244: 'argument' : conversion from 'const double' to 'const int', possible loss of data
5 G:\C++\CDaima\TemplateDemo02\TemplateDemo02.cpp(11) : 　　warning C4244: 'argument' : conversion from 'const double' to 'const int', possible loss of data
6
7 TemplateDemo02.obj - 0 error(s), 2 warning(s)