[PO] Przeciążanie operatorów cz. II - dodawanie stringów

// ConsoleApplication3.cpp : Defines the entry point for the console application.
//
#define use_CRT_SECURE_NO_WARNINGS // to samo w Debug --> [nazwa pliku] Properties --> C/C++ --> Preprocessor Definitions : _CRT_SECURE_NO_WARNINGS
#include "stdafx.h"
#include <conio.h>
#include <iostream>
#include <malloc.h>
#include <cstring>

class String
{
public:
    String(char*);
    String(const String &);

    String& operator = (const String &);
    String& operator + (const String &);

    char* Txt() const;

    char & operator [] (int t);

private:
    char* napis;
};


String::String(char* str)
{
    this->napis = (char*)malloc(sizeof(char) * strlen(str) + 1);
    strcpy(this->napis, str);
}

String::String(const String &str)
{
    this->napis = (char*)malloc(sizeof(char) * strlen(str.napis) + 1);
    strcpy(this->napis, str.napis);
}

String& String::operator = (const String &str)
{
    this->napis = (char*)malloc(sizeof(char) * strlen(str.napis) + 1);
    strcpy(this->napis, str.napis);
    return *this;
}

String& String::operator + (const String &str)
{
    this->napis = (char*)realloc(this->napis, sizeof(char) * (strlen(this->napis) + strlen(str.napis)) + 1);
    strcat(this->napis, str.napis);

    return *this;
}

char & String::operator[](int t)
{
    return this->napis[t];
}

char* String::Txt() const
{
    return this->napis;
}

std::ostream& operator << (std::ostream &s, const String &str)
{
    return s << str.Txt();
}

int main()
{
    String str("Napis 1");
    String str2(" Napis 2");

    printf("%s\n", str.Txt());

    str = str2;

    printf("%s\n", str.Txt());

    String str3(" Napis 3");

    str = str2 + str3;

    printf("%s\n", str.Txt());

    std::cout << str << std::endl; //przeciazanie << coutem

    printf("%c\n", str[3]); //wypisuje trzeci indeks (czwarty znak) z tablicy str

    _getch();
    return 0;
}