I am a student and I use dev-c++ with g++ (GCC) 3.4.2 (mingw-special)to compile my program. When I compile my program, I get some errormessage like this:
=====================================================In member function `MyType* Stack<MyType>::Delete(MyType&)': 108 there are no arguments to `IsEmpty' that depend on a templateparameter, so a declaration of `IsEmpty' must be available 108 (if you use `-fpermissive', G++ will accept your code, butallowing the use of an undeclared name is deprecated) 108 there are no arguments to `Empty' that depend on a templateparameter, so a declaration of `Empty' must be available 109 `array' undeclared (first use this function) (Each undeclared identifier is reported only once for eachfunction it appears in.) 109 `top' undeclared (first use this function)=====================================================
and I list my code below:=====================================================#include <iostream>const int DefaultSize = 20;using namespace std;
template <class MyType>class Bag{public: Bag(int MaxSize=DefaultSize); //建構子 virtual ~Bag(); //解構子
virtual void Add(MyType); // 插入element到bag裡面 virtual MyType* Delete(MyType&); //從bag刪除element
virtual bool IsFull(); //當bag是滿的傳回true,反之則為false virtual bool IsEmpty(); // 當bag是空的傳回true,反之則為falseprotected: virtual void Full(); //bag是滿的就會執行 virtual void Empty(); // bag是空的就會執行
MyType *array; int MaxSize; //array的大小 int top; //在array中含括element的最高位置};
template <class MyType>class Stack : public Bag<MyType>{ public: Stack(int MaxSize=DefaultSize); //建構子 ~Stack(); //解構子 MyType* Delete(MyType&);};
int main(void){ Bag <int> b(5); // 利用Bag的建構子建立一個大小為5的array
Stack <int> s(5); //利用Stack的建構子建立一個大小為5的array
b.Add(1);b.Add(2);b.Add(3);b.Add(4);b.Add(5); //用Bag::Add 呼叫 Bag::Full,Bag::IsFull s.Add(7);s.Add(8);s.Add(9);s.Add(10);s.Add(11);
int x; b.Delete(x); cout << "x = " << x << endl; s.Delete(x); cout << "x = " << x << endl; //system("pause"); return 0;}
template<class MyType>Bag<MyType>::Bag(int MaxBagSize):MaxSize(MaxBagSize){ array = new MyType[MaxSize];top=-1;}
template<class MyType>Bag<MyType>::~Bag(){delete [] array ;}
template<class MyType>inline bool Bag<MyType>::IsEmpty(){ if(top==-1) return true ; else return false;}
template<class MyType>inline bool Bag<MyType>::IsFull(){ if(top==MaxSize-1) return true ; else return false;}
template<class MyType>inline void Bag<MyType>::Full(){ cerr << "DATA STRUCTURE IS FULL" << endl;}
template<class MyType>inline void Bag<MyType>::Empty(){ cerr << "DATA STRUCTURE IS Empty" << endl;}
template<class MyType>void Bag<MyType>::Add(const MyType x){ if(IsFull())Full();else array[++top]=x;}
template<class MyType>MyType* Bag<MyType>::Delete(MyType& x){ if(IsEmpty()){Empty(); return 0;} int deletePos = top/2 ; x=array[deletePos]; for (int index = deletePos ; index<top ; index++) array[index]= array[index+1]; top--;return &x;}
template<class MyType>Stack<MyType>::Stack(int MaxStackSize):Bag<MyType>(MaxStackSize){}//constructor for stack calls constructor for bag
template<class MyType>Stack<MyType>::~Stack(){} //用來確定array被刪除
template<class MyType>MyType* Stack<MyType>::Delete(MyType& x){ if(IsEmpty()){Empty();return 0 ; } x=array[top--]; return &x;}=====================================================
The class Stack is derived from the class Bag, and all the datamembers are inherited from Bag.
Can any one help?
RegardsAuxo
