How to make the operator= in a Vector class? - c++

Question

I don't know, which is not correct, the copy constructor or the operator=. I tested with two "tombs", and the printer is working, but at the end of the program the compiler said "debug assertion failed".
#pragma once
#include <cstdio>
#include <cmath>
#include <iostream>
#include <cstdlib>
class tomb {
private:
double *adat;
int szam;
public:
tomb(){
adat = NULL;
szam = 0;
}
tomb(const tomb &u) {
adat = u.adat;
szam = u.szam;
};
int meret()const {
return szam;
}
~tomb() {
delete[] adat;
}
double & operator[](int n) {
return adat[n];
}
const double & operator[](int n)const {
return adat[n];
}
const tomb &operator=(const tomb &a) {
adat = a.adat;
szam = a.szam;
return *this;
}
tomb elso_valahany(int n) {
}
void push_back(const double &a) {
double *tmp;
tmp = new double[szam+1];
for (int i = 0; i < szam; i++)
{
tmp[i] = adat[i];
}
tmp[szam] = a;
delete[] adat;
adat = tmp;
++szam;
}
void Kiir()const {
for (int i = 0; i < szam; i++)
{
std::cout << adat[i] << "\n";
}
}
};

Answer 1

As per the comments, I'll show you how to do a deep copy: every time you copy the class, you will not be copying just the pointer to the data, but the whole vector instead.
Also, for the sake of simplicity, I'll use std::vector:
#pragma once
#include <cstdio>
#include <cmath>
#include <iostream>
#include <cstdlib>
#include <vector>
class tomb {
private:
std::vector<double> adat;
int szam;
public:
tomb(){
szam = 0;
}
tomb(const tomb &u) : adat(u.adat), szam(u.szam)
{
adat = u.adat;
szam = u.szam;
};
int meret() const {
return szam;
}
~tomb() {
}
double & operator[](int n) const {
return adat[n];
}
const double & operator[](int n) const {
return adat[n];
}
tomb& operator=(const tomb &a) {
adat = a.adat;
szam = a.szam;
return *this;
}
tomb elso_valahany(int n) {
}
void push_back(const double &a) {
adat.push_back(a);
++szam;
}
void Kiir()const {
for (int i = 0; i < szam; i++)
{
std::cout << adat[i] << "\n";
}
}
I haven't compiled/tested, but it should be fine now, as the memory management is done by std copy constructors!