Singleton 模式文件

// .h
//
#pragma once

#include <iostream>
using namespace std;

#define DECLEAR_SINGLE_INSTANCE(T)                             \
  private:static T m_SingletonInstance;                      \
  public:static T* Instance(){ return &m_SingletonInstance;}

#define IMPLEMENT_SINGLE_INSTANCE(T)         \
T T::m_SingletonInstance;

class CSystemConfig
{
public:
  CSystemConfig(){}
  ~CSystemConfig(){}
public:
  DECLEAR_SINGLE_INSTANCE(CSystemConfig);
public:
  void Initialize()
  {
    cout<<""<<endl;
    cout<<""<<endl;
  }
  
};


测试文件

#include "Singleton.h"

IMPLEMENT_SINGLE_INSTANCE(CSystemConfig) // 怎么解释这句话的功能呢?

void main()
{
  CSystemConfig::Instance()->Initialize();
}