我不知道代码有什么问题，但在 Visual Studio 中不断收到这些错误消息。
Error 18 error C1903: unable to recover from previous error(s); 29
Error 15 error C2039: 'Node' : is not a member of '`global namespace'' 23
Error 6 error C2039: 'node_count' : is not a member of '`global namespace'' 13
Error 5 error C2039: 'node_count_' : is not a member of '`global namespace'' 10
Error 3 error C2059: syntax error : '<'
Error 13 error C2059: syntax error : '<' 23
Error 11 error C2086: 'int CS170::List' : redefinition 23
Error 7 error C2143: syntax error : missing ';' before '{' 14
Error 1 error C2143: syntax error : missing ';' before '<' 10
Error 9 error C2143: syntax error : missing ';' before '<' 23
Error 8 error C2447: '{' : missing function header (old-style formal list?) 14
Error 17 error C2588: '::~Node' : illegal global destructor 29
Error 2 error C2988: unrecognizable template declaration/definition 10
Error 12 error C2988: unrecognizable template declaration/definition 23
Error 4 error C3083: 'Node': the symbol to the left of a '::' 10
Error 14 error C3083: 'Node': the symbol to the left of a '::' must be a type 23
Error 16 error C3083: 'Node': the symbol to the left of a '::' must be a type 29
Error 10 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 23
这是头文件；
////////////////////////////////////////////////////////////////////////////////
#ifndef LIST_H
#define LIST_H
////////////////////////////////////////////////////////////////////////////////
#include <iostream> /* ostream, endl */
namespace CS170
{
template <typename T> class List;
template <typename T>
std::ostream & operator<<(std::ostream & os, const List<T> &list);
template <typename T>
class List
{
public:
// Default constructor
List(void);
// Copy constructor for constructing a list from an existing list
List(const List &list);
// Construct a list from a T array
List(const T *array, int size);
// Destructor
~List(void);
void push_front(const T& Value); // adds the item to the front of the list
void push_back(const T& Value); // adds the item to the end of the list
void pop_front(void); // removes the first item in the list
T front(void) const; // retrieves the first item in the list
int size(void) const; // returns the number of items in the list
bool empty(void) const; // true if empty, else false
void clear(void); // clears the list
// Overloaded assignment operator (=) for assigning one list to another
List& operator=(const List &list);
// Overloaded addition operator (+) for adding two lists
List operator+(const List &list) const;
// Overloaded addition/assignment (+=) for adding to a list "in place"
List& operator+=(const List &list);
// Overloaded subscript operators
const T& operator[](int index) const;
T& operator[](int index);
// Output operator for printing lists (<<)
friend std::ostream & operator<< <T> (std::ostream & os, const List &list);
// Returns the number of Nodes that have been created
static int node_count(void);
private:
// Used to build the linked list
struct Node
{
Node *next; // pointer to the next Node
T data; // the actual data in the node
Node(T value); // non-default constructor (conversion)
~Node(void); // destructor
static int node_count_; // number of Nodes created
};
Node *head_; // pointer to the head of the list
Node *tail_; // pointer to the last node
int size_; // number of items on the list
// All nodes are created in this method
Node *new_node(const T& data) const;
};
} // namespace CS170
#include "List.cpp"
#endif
////////////////////////////////////////////////////////////////////////////////
这是cpp文件；
namespace CS170
{
// static members
template <typename T>
int List<T>::Node::node_count_ = 0;
template <typename T>
int List<T>::node_count(void)
{
return Node::node_count_;
}
// List::Node methods
template <typename T>
List<T>::Node::Node(T value) : data(value)
{
node_count_++;
}
template <typename T>
List<T>::Node::~Node(void)
{
node_count_--;
}
// public methods
template <typename T>
void List<T>::clear(void)
{
while (!empty())
pop_front();
}
// private methods
template <typename T>
typename List<T>::Node *List<T>::new_node(const T& data) const
{
Node *node = new Node(data); // create the node
node->next = 0; // no next pointer yet
return node;
}
} // namespace CS170
// non-members
#include <iomanip>
template <typename T>
std::ostream &CS170::operator<<(std::ostream & os, const CS170::List<T> &list)
{
// Start at the top
typename CS170::List<T>::Node *pnode = list.head_;
// Print each item
while (pnode != 0)
{
os << std::setw(4) << pnode->data;
pnode = pnode->next;
}
os << std::endl;
return os;
}
谢谢...