C++模板的理解

<span style="font-size:18px;">#include <iostream>#include <typeinfo>using namespace std;//using std::cout;//using std::cin;//using std::endl;template<typename T,int maxSize=100> class  stack{public:void push(T& a);T pop();stack( int maxSize);//int maxSizevoid show();bool isFull();bool isEmpty();int  getSize();T  at(int i);stack<T,maxSize>& operator=(stack<T,maxSize>& a){cout<<"a-jNum:"<<a.getSize()<<endl;cout<<"a-maxNum:"<<a.getMaxSize()<<endl;cout <<"a-id："<<typeid(a).name()<<endl;delete[] m_pobj;m_pobj=NULL;int capcity=a.getMaxSize();m_iMaxSize=a.getMaxSize();m_pobj=new T[capcity];m_iSize=a.getSize();cout<<"this-jNum:"<<getSize()<<endl;cout<<"this-MaxNum:"<<getMaxSize()<<endl;cout<<"at"<<endl;for (int i=0;i<m_iSize;i++)m_pobj[i]=a.at(i);show();return *this;}int getMaxSize();~stack();private:T * m_pobj;int m_iSize;int m_iMaxSize;};template <typename T,int maxSize> int stack<T,maxSize>::getMaxSize(){return m_iMaxSize;}//模板 就是先定义类型  在定义返回值 类名<专门化>  到作用域 ::  函数名（参数）:数据成员的默认值//定义变量的时候   stack<int , 30 >  这样其实是一个数据类型  如同int型。相当一个可变组合数据类型 //stack<int , 30 >中30 都是一个类型了。</span>template <typename T,int maxSize> int  stack<T,maxSize>::getSize()//maxSize 的名字不能改变，不然会报错。{return m_iSize;}template <typename T,int maxSize> T  stack<T,maxSize>::at(int i)//maxSize 的名字不能改变，不然会报错。{return m_pobj[i];}template<typename T,int maxSize> stack<T, maxSize >::stack(int maxSize )//:m_iMaxSize=maxSize//int maxSize{m_iMaxSize=maxSize;m_iSize=0;m_pobj=new T[m_iMaxSize];cout<<"m_iMaxSize:"<<m_iMaxSize<<endl;cout<<"maxSize:"<<maxSize<<endl;}template<typename T,int maxSize> void stack<T, maxSize >::push(T& a){m_pobj[m_iSize++]=a;}template<typename T,int maxSize> void stack<T, maxSize >::show(){for (int i=0;i<m_iSize;i++){cout<<m_pobj[i]<<",";}}template <typename T,int maxSize> T stack<T,maxSize>::pop(){m_iSize--;return m_pobj[m_iSize];}template <typename T,int maxSize> bool stack<T,maxSize>::isFull(){return m_iSize>=m_iMaxSize;}template<typename T,int maxSize> bool stack<T,maxSize>::isEmpty(){return m_iSize==0;}template<typename T,int maxSize> stack<T,maxSize> ::~stack(){delete[] m_pobj;}//函数operate 运算符重载不能卸载类外，要写在类外就用friend 函数。</span>//template<typename T int maxSize>  stack<T,maxSize> stack<T,maxSize>::operator=(stack<T,maxSize> a)//{//delete[] m_pobj;//int capcity=m_iMaxSize;//m_pobj=new T[capcity];//return *this;//}int main(){int a;int sizeMax=50;stack<int,80> stackTest1(sizeMax);stack<int> stackTest2(sizeMax);cout <<"stackTest1-id："<<typeid(stackTest1).name()<<endl;cout <<"stackTest2-id："<<typeid(stackTest2).name()<<endl;</span>stack<int,30> stackobj(sizeMax);//stack<int> stackobj(sizeMax);//,30去掉的画  后面的赋值 newstack=stackobj;就编译不过，因为不是同一个数据类型了。for (int k=0;k<sizeMax;k++){stackobj.push(k);}cout<<endl;cout<<"show push"<<endl;stackobj.show();cout<<endl;cout<<"show pop"<<endl;for (int j=0;j<sizeMax;j++){cout<<stackobj.pop()<<", ";}for (int k=0;k<sizeMax;k++){stackobj.push(k);}cout<<endl;cout<<"show push2"<<endl;stackobj.show();stack<int,30> newstack(70);cout<<"newstackNum:"<<newstack.getSize()<<endl;newstack=stackobj;cout<<"newstackNum2:"<<newstack.getSize()<<endl;cin>>a;}</span>