C++设计模式-Observer观察者模式

#include <iostream>
#include <sstream>
#include <map>
#include <signal.h>
#include <stdio.h>
#include <memory>
#include <vector>
#include <set>
#include <assert.h>
#include <unordered_map>
#include <boost/thread.hpp>
#include <boost/bind/bind.hpp>
#include <queue>
#include <Winsock2.h>  

#include <boost/progress.hpp>
#include <boost/date_time/gregorian/gregorian.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/ref.hpp>
#include <functional>
#include <numeric>

using namespace boost;
using namespace std;

class CObservable : boost::noncopyable
{
public:
    typedef boost::function<void(int)> Func;

    CObservable()
        : m_observerId(0)
    {}
    virtual ~CObservable(){}

    int Attach(const Func& f)
    {
        int k = m_observerId++;
        m_observers[k] = f;

        return k;
    }

    void Detach(int key)
    {
        m_observers.erase(key);
    }

    void Notify( int i )
    {
        for ( auto it = m_observers.begin(); it != m_observers.end(); it++ )
        {
            it->second(i);
        }
    }
private:
    int m_observerId;
    std::map<int, Func> m_observers;
};

struct stA
{
    void print(int a)
    {
        cout << "stA=" << a << endl;
    }
};

void print(int a)
{
    cout << "print=" << a << endl;
}

int main(int argc, char **argv)
{
    CObservable myObservable;
    myObservable.Attach(print);
    stA t;
    boost::function<void(int)> f = boost::bind(&stA::print, &t, _1);
    int key = myObservable.Attach(f);

    int a = 100;
    myObservable.Notify(a);

    myObservable.Detach(key);
    a = 999;
    myObservable.Notify(a);

    getchar();
    return 0;
}