C++模板类的继承1 ：模板类继承模板类

       大学时代旧作。

      模板类的继承是C++中较为高级的一种用法，其语法与普通C++类的继承略有差别。本文实例演示了一个通过C++模板类继承实现排序算法的案例。代码如下：

1.   实现List基类

#ifndef LIST_H#define LIST_H#include <iostream>using std::cout;using std::endl; enum Error_code { underflow, overflow, range_error, success, not_present,fail};const int max_list = 100; template <class List_entry>class List{       // methods of List ADTpublic:        List();       int size() const;       bool full() const;       bool empty() const;       void clear();       void traverse(void(*vist)(List_entry&));  // Traverse every elements in the List       Error_code retrieve(int position, List_entry &x) const;       Error_code replace(int position, const List_entry& x);       Error_code  remove(int position, List_entry& x);       Error_code  insert(int position, const List_entry &x); protected:        // The contiguous implementation is based on the array       int count;       List_entry entry[max_list];};// constructortemplate<class List_entry>List<List_entry>:: List(){       count = 0;}/***** 其余代码略***********/#endif

2. 从模板类中派生一个模板子类

#ifndef SORTABLE_LIST#define SORTABLE_LIST #include "list.h" template<class Record>class Sortable_list : public List<Record>{   public:          Sortable_list();           // Insertion sorting          void insertion_sort();           // Selection sorting          void selection_sort();          int max_key(int low, int high);          void swap(int low, int high);           // Shell sorting          void shell_sort();          void sort_interval(int low, int increment);        // Quick sorting          void quick_sort();          void recursive_quick_sort(int low, int high);          int partition(int low, int high);           // Heap sorting          void heap_sort();          void insert_heap(const Record& current, int low, int high);          void build_heap(); };// 派生类的构造函数，注意其语法差别template<class Record>Sortable_list<Record>::Sortable_list():List<Record>(){}/********************其余代码略**************************************/#endif

3. 测试代码

#include <iostream>using std::cout;using std::endl; #include "list.h"#include "Sortable_list.h" void print(int &a){       cout<<a<<" ";}int main(){    Sortable_list<int> myList;       myList.insert(0,6);       myList.insert(0,56);       myList.insert(0,7);       myList.insert(2,57);       myList.insert(1,4);       myList.insert(3,23);       myList.insert(0,9);       myList.insert(5,45);       myList.insert(4,17);       myList.insert(0,7);       myList.insert(6,89);       myList.insert(6,34);       myList.insert(2,35);         // Sortable list to test different soring methods    Sortable_list<int> myList2 = myList;       Sortable_list<int> myList3 = myList;       Sortable_list<int> myList4 = myList;       Sortable_list<int> myList5 = myList;        // Print out the original list       cout<<"All the entries in the original list: "<<endl;       myList.traverse(print);       cout<<endl;         // Test the insert sorting       cout<<"After the insert soring, we get:"<<endl;       myList.insertion_sort();       myList.traverse(print);    cout<<endl;     // Test the selection sorting       cout<<"After the insert soring, we get:"<<endl;       myList2.selection_sort();       myList2.traverse(print);    cout<<endl;     // Test the shell sorting    cout<<"After the  shell sort,we get :"<<endl;    myList3.shell_sort();     myList3.traverse(print);       cout<<endl;           // Test the quick sorting    cout<<"After the  quick sort,we get :"<<endl;    myList4.quick_sort();     myList4.traverse(print);       cout<<endl;            // Test the heap sorting    cout<<"After the  quick sort,we get :"<<endl;    myList5.heap_sort();     myList5.traverse(print);       cout<<endl;    return 0; }