#include<iostream>
#include<cstring>



class MyString
{
private:
    char* data;
    size_t size;
    size_t capacity;

public:
    //默认构造函数
    MyString():data(nullptr),size(0),capacity(0){};
    //拷贝构造函数
    MyString(const char*str){
        size_t len=std::strlen(str);
        capacity=size=len;
        data=new char[capacity];
        std::copy(str,str+len,data);
    }
    //析构函数
    ~MyString(){
        delete[] data;
    }
    //重载+运算符
    MyString operator+(const MyString&other)
{
    MyString newStr;
    newStr.size=size+other.size;
    newStr.capacity=capacity+other.capacity;
    newStr.data=new char[newStr.capacity];
    std::copy(data, data + size, newStr.data);
    std::copy(other.data, other.data + other.size, newStr.data + size);
    return newStr;
}
    //重载=运算符
    MyString& operator=(const MyString&str)
    {
        delete[] data;
        size=str.size;
        capacity=str.capacity;
        data=new char[str.capacity];
        std::copy(str.data,str.data+str.size,data);
        return *this;
    }
    //string输出
    friend std::ostream& operator<<(std::ostream& os,const MyString& str);
    
};
std::ostream& operator<<(std::ostream& os,const MyString& str)
{
    os<<str.data;
    return os;
}

int main()
{
    MyString str1 = "Hello";
    MyString str2 = "World";
    MyString str3 = str1 + str2;

    std::cout << "str1: " << str1 << std::endl;
    std::cout << "str2: " << str2 << std::endl;
    std::cout << "str3: " << str3 << std::endl;

   

    return 0;
}