设计模式之单例模式

单例模式(Singleton)也属于创建型模式，解决的是在程序里只能生成一个实例的问题。
以下为该模式的C++实现，可到本人github网页https://github.com/hugewave/DesignPattern下载

/*
 * Example of 'SingleTon' design pattern.
 * Copyright (C) 2016 Leo Wang 
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see .
 */
#include 
#include 
using namespace std;

class CSingleTon
{
public:
    int m_value;
    void SetValue(int value)
    {
        m_value=value;
    };

    int GetValue()
    {
        return m_value;
    };
private:
    static CSingleTon* cp_inst;
    CSingleTon(){m_value=0;};
public:
    static CSingleTon* Instance();
    static void Destroy()
    {
        if(cp_inst!=NULL)
            delete cp_inst;
        cp_inst=NULL;
    };
};

CSingleTon* CSingleTon::cp_inst=NULL;

CSingleTon* CSingleTon::Instance()
{
    if(cp_inst==NULL)
    {
        cp_inst=new CSingleTon();
    }

    return cp_inst;
};

void main()
{
    CSingleTon* cp_inst1=CSingleTon::Instance();
    int v1=cp_inst1->GetValue();
    int v2=1;
    cp_inst1->SetValue(v2);
    CSingleTon* cp_inst2=CSingleTon::Instance();
    int v3=cp_inst2->GetValue();
    cout<<"v1 is "<cout<<"v2 is "<cout<<"v3 is "<