我正在创建一个包含内部朋友Node类的PriorityQueue模板类。当我尝试编译下面的代码时,我现在收到这些错误:
PriorityQueue.h:20:12: error: declaration of ‘class T’
template<typename T> class Node
^
PriorityQueue.h:16:11: error: shadows template parm ‘class T’
template <typename T> class PriorityQueue
^
PriorityQueue.h:22:25: error: expected nested-name-specifier
friend typename PriorityQueue<T>;
^
PriorityQueue.h:22:41: error: invalid declarator before ‘;’ token
friend typename PriorityQueue<T>;
^
PriorityQueue.cpp:66:1: error: ‘PriorityQueue<T>::Node’ is not a type
PriorityQueue<T>::Node::Node()
^
PriorityQueue.cpp:66:30: error: ISO C++ forbids declaration of ‘Node’ with no type [-fpermissive]
PriorityQueue<T>::Node::Node()
^
PriorityQueue.cpp:66:30: error: invalid use of dependent type ‘typename PriorityQueue<T>::Node’
PriorityQueue.cpp:74:1: error: ‘PriorityQueue<T>::Node’ is not a type
PriorityQueue<T>::Node::Node(T data, int *index, float priority)
^
PriorityQueue.cpp:74:64:错误:ISO C ++禁止声明'Node'没有类型[-fpermissive] PriorityQueue :: Node :: Node(T数据,int *索引,浮点优先级) ^ PriorityQueue.cpp:74:64:错误:无效使用依赖类型'typename PriorityQueue :: Node'
PriorityQueue.h:
#ifndef PRIORITYQUEUE_H_
#define PRIORITYQUEUE_H_
#include <vector>
#include <map>
using namespace std;
template<typename T> class Node
template <typename T> class PriorityQueue
{
public:
template<typename T> class Node
{
friend typename PriorityQueue<T>;
private:
T data;
int *index;
float priority;
public:
Node();
Node(T data, int *index, float priority);
};
private:
vector<T> v;
map<T, int*> m;
int vSize;
public:
PriorityQueue();
~PriorityQueue();
void insert(T obj, float priority);
T front();
T pop();
bool isEmpty();
void changePriority(T obj, float new_priority);
};
#endif
PriorityQueue.cpp:
#include "PriorityQueue.h"
#include <vector>
#include <map>
using namespace std;
template<class T>
PriorityQueue<T>::PriorityQueue()
{
vector<T> v;
map<T, int*> m;
this.vSize = 0;
}
template<class T>
PriorityQueue<T>::~PriorityQueue()
{
}
template<class T>
void PriorityQueue<T>::insert(T obj, float priority)
{
Node<T> n = new Node<T>(obj, vSize, priority);
v[vSize] = n;
m.insert(obj, vSize);
vSize++;
}
template<class T>
T PriorityQueue<T>::front()
{
}
template<class T>
T PriorityQueue<T>::pop()
{
}
template<class T>
bool PriorityQueue<T>::isEmpty()
{
bool b = false;
if(vSize > 0)
{
b = true;
return b;
}
else
{
return b;
}
}
template<class T>
void PriorityQueue<T>::changePriority(T obj, float new_priority)
{
}
template<class T>
PriorityQueue<T>::Node::Node()
{
data = NULL;
index = 0;
priority = 0.0;
}
template<class T>
PriorityQueue<T>::Node::Node(T data, int *index, float priority)
{
this->data = data;
this->index = index;
this->priority = priority;
}
非常感谢任何帮助。
答案 0 :(得分:2)
在您向前发布Node之后,您似乎错过了一个分号。这可能是编译器头痛的根源。