Thread: Compile Errors, Please Help

Code:

Hello,
I am doing an exercise in my book and im suing the answer codes provided, and it still does not work, here is the code:
#include <stdafx.h>
#include <iostream>
#include <string.h>
#include <stdlib.h>
using namespace std;

class String {
private:
	char *ptr;
public:
	String();
	String(char *s);
	String(const String &src);
	~String();

	String& operator=(const String &src) {cpy(src.ptr); return *this;}
	String& operator=(char *s) {cpy(s); return *this;}

	String operator+(char *s);
	int operator==(const String &other);
	operator char*() {return ptr;}
	operator int() {return atoi(ptr);}  //this is the convert to int function

	void cat(char *s);
	void cpy(char *s);
};


int main() {
	String a, b, c;
	a = "I ";
	b = "am ";
	c = "so ";
	String d = a + b + c + "very happy!\n";
	cout << d;
	return 0;
}


//declaring String class member functions
String::String() {
	ptr = new char[1];
	ptr[0] = '\0';
}

String::String(char *s) {
	int n = strlen(s);
	ptr = new char[n + 1];
	strcpy(ptr, s);
}

String::String(const String &src) {
	int n = strlen(src.ptr);
	ptr = new char[n + 1];
	strcpy(ptr, src.ptr);
}

String::~String() {
	delete [] ptr;
}

int String::operator==(const String &other) {
	return (strcmp(ptr, other.ptr) == 0);
}

String String::operator+(char *s) {
	String new_str(ptr);
	new_str.cat(s);
	return new_str;
}

//cpy- copy string function
void String::cpy(char *s) {
	delete [] ptr;
	int n = strlen(s);
	ptr = new char[n + 1];
	strcpy(ptr, s);
}

//cat- concatenation string function
void String::cat(char *s) {
	int n = strlen(ptr) + strlen(s);
	char *p1 = new char[n + 1];
	strcpy(p1, ptr);
	strcat(p1, s);
	delete [] ptr;
	ptr = p1;
}

okay, so the exercies was to add a convert to int function which is marked above, the code compiled fine before i added it, but now i add it and it does not, please help.

please specify an example if you can...