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 <http://www.gnu.org/licenses/>. */#include <stdio.h>#include <iostream>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 "<<v1<<endl;    cout<<"v2 is "<<v2<<endl;    cout<<"v3 is "<<v3<<endl;    CSingleTon::Destroy();};