小编3mr*_*3mr的帖子

我试图了解重载 - >运算符是如何工作的.我有以下课程

class Message {

public:
    Message(string message) :m_text(message) {}
    void printText() {
        cout << "text is " << m_text << endl;
    }
    string m_text;
};


class MessagePointerWrapper
{
public:

    MessagePointerWrapper(string message)  {
        m_message = std::make_unique<Message>(message);
    }

    Message* operator->() {

        return m_message.get();
    }

    std::unique_ptr<Message> m_message;

};

int main(int argc, char** argv)
{

    MessagePointerWrapper messageWrapper =  MessagePointerWrapper("Hello World");
    messageWrapper.m_message->printText();
    messageWrapper->m_text = "PQR";
    messageWrapper.m_message->printText();
}

该MessageWrapper级的->运算符重载以返回Message*.所以在主要方法中,当我调用messageWrapper->它返回的是一个Message*.通常当我有一个指针时,我需要使用->运算符或deference运算符来访问该对象.根据该逻辑,为了访问对象的m_text可用性Message …

我编写了以下代码来解释运算符new

#include <iostream>

using namespace std;




class Dog {

public:
    Dog() {
        cout << "Dog constructed\n";
    }

    //overriding the new operator of the class and explicitely doing what it internally does
    void* operator new(size_t n) {
        cout << "operator new overriden in Dog class called size_t n = " << n << " Sizeof(Dog) = "<< sizeof(Dog) << endl;

        //Allocating the memory  by calling the global operator new 
        void* storage = ::operator new (n);

        // you can now create the …