.h不能通过，.cpp却通过了

[qinken547]

BinaryTree.h

#ifndef BINARYTREE_H_INCLUDED
#define BINARYTREE_H_INCLUDED


#include <iostream>

using namespace std;


template<class T>
struct BTNode
{
BTNode(){ lChild=rChild=NULL;}
BTNode(const T& x)
{
element=x; lChild=rChild=NULL;
     }
BTNode(const T& x, BTNode<T>* l,BTNode<T>* r)
{
element=x; lChild=l; rChild=r;
}
T element;
BTNode<T>* lChild, *rChild;
};



template<class T>
void Visit(T& x)
{
	cout<<x<<"  ";
}

template <class T>
class BinaryTree
{
public:
	BinaryTree(){root=NULL;}
	~BinaryTree(){};
protected:
	BTNode<T>* root;
public:
	bool Root(T& x)const;
	void MakeTree(const T& x, BinaryTree<T> & left, BinaryTree<T> & right);
	void PreOrder(void (*Visit)(T& x));
private:
	void PreOrder(void (*Visit)(T& x),BTNode<T>* t);
public:
	//void Clear(void);
};


#endif // BINARYTREE_H_INCLUDED

BinaryTre.cpp

/*
** Copyright (C) QPSOFT.COM All rights reserved.
*/

#include "BinaryTree.h"

//template <class T>
//BinaryTree<T>::~BinaryTree()
//{
//}

template<typename T>
bool BinaryTree<T>::Root(T& x)const
{
	if(root){
		x=root->element; return true;
	}
	else return false;
}

template<typename T>
void BinaryTree<T>::MakeTree(const T& x, BinaryTree<T>& left, BinaryTree<T>& right)
{
	if(root||&left==&right) return;
	root=new BTNode<T>(x,left.root, right.root);
	left.root=right.root=NULL;
}

template <class T>
void BinaryTree<T>::PreOrder(void (*Visit)(T& x))
{
	PreOrder(Visit,root);
}


template <class T>
void BinaryTree<T>::PreOrder(void (*Visit)(T& x),BTNode<T>* t)
{
	if (t){
		Visit(t->element);
		PreOrder(Visit,t->lChild);
		PreOrder(Visit,t->rChild);
		}
}

main.cpp

#include "BinaryTree.h"

void main(void)
{
	BinaryTree<char> a,b,x,y,z;   
	y.MakeTree('E',a,b);   
	z.MakeTree('F',a,b);          
	x.MakeTree('C',y,z);          
	y.MakeTree('D',a,b);          
	z.MakeTree('B',y,x);       
	z.PreOrder(Visit);
	x.PreOrder(Visit); y.PreOrder(Visit);
}

main函数中用BinaryTree.h就出现如下错误：
1>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall BinaryTree<char>::PreOrder(void (__cdecl*)(char &))" (?PreOrder@?$BinaryTree@D@@QAEXP6AXAAD@Z@Z) referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall BinaryTree<char>::MakeTree(char const &,class BinaryTree<char> &,class BinaryTree<char> &)" (?MakeTree@?$BinaryTree@D@@QAEXABDAAV1@1@Z) referenced in function _main
1>D:\c++\hfm\Debug\hfm.exe : fatal error LNK1120: 2 unresolved externals

用.cpp却运行正常,在VS2008和CODEBLOCKS中都试过，都出现这样的问题...

[冻结]

模板要放在一个文件中，可以都放在.h文件中。

[冻结]

现在的编译器，基本不支持模板的分离编译。

[qinken547]

OK，多谢楼上的，结贴不解释.....

[高性能架构探索]

模板的声明与定义 必须在同一个文件里面