参考网址:
DesignPatterns (github.com)
注意
主要用于全局变量(单例模式)
代码
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| #include<iostream>
template<class T>
class Singleton
{
public:
Singleton(const Singleton&) = delete;
Singleton& operator=(const Singleton&) = delete;
Singleton():m_pInstance(nullptr){}
virtual ~Singleton(){
delete m_pInstance;
}
T* getInstance()
{
if(m_pInstance == nullptr)
{
m_pInstance = new T();
}
return m_pInstance;
}
private:
T* m_pInstance;
};
class A
{
public:
static A* getInstance()
{
static Singleton<A> singleton;
return singleton.getInstance();
}
void test()
{
std::cout<<"A"<<std::endl;
}
};
int main()
{
A* a = A::getInstance();
a->test();
return 0;
}
|
