代码如下所示：

复制代码 代码如下:

#include <iostream>

template <typename T>

class double_linked

{

struct node

{

T data;

node* prev;

node* next;

node(T t, node* p, node* n) : data(t), prev(p), next(n) {}

};

node* head;

node* tail;

public:

double_linked() : head( NULL ), tail ( NULL ) {}

template<int N>

double_linked( T (&arr) [N]) : head( NULL ), tail ( NULL )

{

for( int i(0); i != N; ++i)

push_back(arr[i]);

}

bool empty() const { return ( !head || !tail ); }

operator bool() const { return !empty(); }

void push_back(T);

void push_front(T);

T pop_back();

T pop_front();

~double_linked()

{

while(head)

{

node* temp(head);

head=head->next;

delete temp;

}

}

};

template <typename T>

void double_linked<T>::push_back(T data)

{

tail = new node(data, tail, NULL);

if( tail->prev )

tail->prev->next = tail;

if( empty() )

head = tail;

}

template <typename T>

void double_linked<T>::push_front(T data)

{

head = new node(data, NULL, head);

if( head->next )

head->next->prev = head;

if( empty() )

tail = head;

}

template<typename T>

T double_linked<T>::pop_back()

{

if( empty() )

throw("double_linked : list empty");

node* temp(tail);

T data( tail->data );

tail = tail->prev ;

if( tail )

tail->next = NULL;

else

head = NULL ;

delete temp;

return data;

}

template<typename T>

T double_linked<T>::pop_front()

{

if( empty() )

throw("double_linked : list empty");

node* temp(head);

T data( head->data );

head = head->next ;

if( head )

head->prev = NULL;

else

tail = NULL;

delete temp;

return data;

}

int main()

{

int arr[] = { 4, 6, 8, 32, 19 } ;

double_linked<int> dlist ( arr );

dlist.push_back( 11 );

dlist.push_front( 100 );

while( dlist )

std::cout << dlist.pop_back() << " ";

}