c++模板

模板

//T是模板参数，tempate声明模板的关键字，typename声明 模板参数的关键字

Template<typename T>//template<class T>

 class stack{

 private:

 vector<T> elems;

 publice:

 void push(T elem){

  elems.push_back(elem);

}

 void pop(){

 if(elems.size()>0)

 elems.pop_back();

 else

 cout<<"栈为空"<<endl;

}

 T top(){

 if(elsems.size()>0)

  return elems.back();

 else

 return NULL;

}

  size_t size(){

 return elems.size();

}

};

Int main(){

 stack<int> stk;

 stk.push(1);

 skk.push(2);

 stk.push(3);

 while(stk.size()>0){

 cout<<stk.top()<<" ";

 stk.pop();

}

}

函数模板

  class A{

 private:

 int num;

Public:

 A(int num){

 this->num = num;

}

 friend ostream& operator<<(ostream &out,A a);

};

Ostream& operator<<(ostream &out,A a){

 out<<a.num;

 return out;

}

Int main()

{

 stack<A> stk;

A a(1);

A b(2);

A c(3);

Stk.push(a);

 stk.push(b);

 stk.push©;

 while()stk.size()>0){

 cout <<stk.top()<<" ";

 stk.pop();

}

}