C++Talk.NET

MirzaD · Guest

Hello
Below you will find the problematic program. It is a string wrapper
class with a bare minimum of functionality to keep things simple.

**Code**

//StringClass.h

#include <iostream>
#include <cstring>

using namespace std;

class StringClass{
char* s;
int size;

public:
char* name;
StringClass();
StringClass(char* string);

~StringClass();

StringClass operator=(StringClass &string);
friend ostream &operator<<(ostream &output, StringClass &string);
};

StringClass::StringClass(){
s = new char[0];
size = 0;
}

StringClass::StringClass(char* string){
size = strlen(string);
s = new char[size + 1];
strcpy(s,string);
}

StringClass::~StringClass(){
cout << "Destructor: " << name << endl;
delete [] s;
}

StringClass StringClass::operator=(StringClass &string){
char* temp;
try{
temp = new char[string.size + 1];
}
catch (bad_alloc ex){
exit(1);
}
strcpy(temp,string.s);
delete [] s;
s = temp;
return *this;
}

ostream &operator<<(ostream &out, StringClass &string){
out << string.s;
return out;
}

//StringClass.cpp

#include "StringClass.h"

using namespace std;

int main(){
StringClass s("test"),t;
s.name = "s";
t.name = "t";
t = s;
cout << "s = " << s << endl << "t = " << t < return 0;
}

**End code**

The above will display the following:
Destructor: t
s = test;
t = $*%
Destructor: t
Destructor: s

Why is the destructor called on t after the assignment takes place?
This would make sense to me if t was a pointer and the destructor was
called on the object it was pointing to (the last reference to the
object was just removed). Any help/clarification is appreciated.
Regards,

Mirza

Victor Bazarov · Guest

MirzaD wrote:

Alf P. Steinbach · Guest

* MirzaD:

MirzaD · Guest

Adding the copy constructor did solve the problem. Thank you very
much.

Mirza

Jay Nabonne · Guest

On Tue, 29 Nov 2005 12:03:15 -0800, MirzaD wrote:

Puppet_Sock · Guest

Alf P. Steinbach wrote:

Victor Bazarov · Guest

Puppet_Sock wrote: