86.运算符重载

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
using namespace std;

class mystring
{
public:
    char *pstr;
    int length;
    mystring():pstr(nullptr),length(0)
    {

    }

    mystring(char *str)
    {
        //获取字符串长度
        this->length = strlen(str) + 1;
        this->pstr = new char[this->length + 1];
        //拷贝
        strcpy(this->pstr, str);
    }

    //拷贝构造
    mystring(const mystring &my)
    {
        this->length = my.length;
        this->pstr = new char[this->length];
        strcpy(this->pstr, my.pstr);
    }

    mystring add(const mystring &my)
    {
        int n = this->length + my.length - 1;
        mystring temp;
        temp.length = n;
        //分配内存
        temp.pstr = new char[temp.length];
        strcpy(temp.pstr, this->pstr);
        //尾部添加
        strcat(temp.pstr, my.pstr);
        return temp;
    }

    //重载加法
    mystring operator +(const mystring &my)
    {
        int n = this->length + my.length - 1;
        mystring temp;
        temp.length = n;
        //分配内存
        temp.pstr = new char[temp.length];
        strcpy(temp.pstr, this->pstr);
        //尾部添加
        strcat(temp.pstr, my.pstr);
        return temp;
    }
};

template<class T>
T add(T a, T b)
{
    return a + b;
}

void main()
{
    mystring str1 = "hello";
    mystring str2 = "world";
    //mystring str3 = str1.add(str2);
    //mystring str3 = str1 + str2;
    mystring str3 = str1.operator+(str2);
    cout << str3.pstr << endl;

    //模板与运算符重载
    cout << add<mystring>(str1, str2).pstr << endl;
    cin.get();
}