Re: Compile error.

This is an simple map, just an exercise. Who can help me fix this
compile issue?Thanks in advance.
#include <string>
#include <vector>
#include <iostream>
using std::vector;
using std::string;
using std::cout;
using std::endl;

template<typename T>
class Map{
    template<typename U>
    struct Pair{
        string name;
        U val;
        Pair(string n ="", U v):name(n),val(v){}
    };
    vector<Pair<T> > vec;
    Map(const Map&);
    Map& operator=(const Map&);
    typedef vector<Pair<T> >::const_iterator CIT;
    typedef vector<Pair<T> >::iterator IT;

public:
    Map(){}
    double& operator[](const string&);
    void print_all()const;};

template<typename T>
T& Map<T>::operator[](const string& name)
{
    IT it = vec.begin();
    IT end = vec.end();
    for(; it != end; ++it){
        if(it->name == name) return it->val;
    }
    vec.push_back(Pair<T>(name,T()));
    return vec.back().val;}

template<typename T>
void Map<T>::print_all()const
{
    for(CIT p = vec.begin(); p != vec.end();++p){
        cout << p->name << ": " << p->val << endl;
    }}

int main()
{
    Map<int> m;
    m["zhu"] = 100;
    m["li"] = 200;
    m.print_all();

}

-*- mode: compilation; default-directory: "e:/tcplex/p2_ch13/" -*-
Compilation started at Sat Nov 15 21:42:28

g++ 13.8.cpp
13.8.cpp:20: error: type `std::vector<Map<T>::Pair<T>,
std::allocator<Map<T>::Pair<T> > >' is not derived from type `Map<T>'
13.8.cpp:20: error: ISO C++ forbids declaration of `const_iterator'
with no type
13.8.cpp:20: error: expected `;' before "CIT"
13.8.cpp:21: error: type `std::vector<Map<T>::Pair<T>,
std::allocator<Map<T>::Pair<T> > >' is not derived from type `Map<T>'
13.8.cpp:21: error: ISO C++ forbids declaration of `iterator' with no
type
13.8.cpp:21: error: expected `;' before "IT"
13.8.cpp:29: error: prototype for `T& Map<T>::operator[](const
std::string&)' does not match any in class `Map<T>'
13.8.cpp:24: error: candidate is: double& Map<T>::operator[](const
std::string&)
13.8.cpp:29: error: template definition of non-template `T&
Map<T>::operator[](const std::string&)'
13.8.cpp: In member function `T& Map<T>::operator[](const
std::string&)':
13.8.cpp:30: error: `IT' was not declared in this scope
13.8.cpp:30: error: expected `;' before "it"
13.8.cpp:31: error: expected `;' before "end"
13.8.cpp:32: error: `it' was not declared in this scope
13.8.cpp:32: error: `end' was not declared in this scope
13.8.cpp: In member function `void Map<T>::print_all() const':
13.8.cpp:41: error: `CIT' was not declared in this scope
13.8.cpp:41: error: expected `;' before "p"
13.8.cpp:41: error: `p' was not declared in this scope

Compilation exited abnormally with code 1 at Sat Nov 15 21:42:28