operator new, new operator, delete new, new delete

不同意义的new和delete

operator前置：原始的内存空间分配
operator后置：原始的内存空间分配+构造与析构

operator new 和 operator delete

• operator new: 和malloc一样，唯一任务是分配原始内存

• operator delete: 释放operator new分配的内存，防止资源泄露

  void* operator new(size_t size);//operator new通常声明void operator delete(void* memory);//operator delete通常声明void* memory =  operator new(sizeof(string));operator delete(memory); 

new operator和delete operator

• new operator: 包括调用operator new申请内存空间，调用构造函数constructor，返回指向该对象的指针

  void * memory= operator new(sizeof(string));//申请内存空间call string::string("memory management") on memory;//内存对象初始化string *ps = static_cast<string*>(memory);//返回指向新对象的指针

• delete operator: 包括调用析构函数，释放申请的内存空间

delete ps;

相当于：

ps->~string;operator delete(ps);

参考：《more effective c++》操作符（operators）章节