C## Class Problems

I need some help on this ASAP as the program is due at 11:00pm.

I have one error left, but I have a feeling once it's fixed I'm going to have several more. That would be my luck.

The error is the title for this problem: declaration of 'OPairType::OPairType(int, int)' outside of class is not definition -fpermissive

Here is my full code:

Header File:

class OPairType{
private:
int x;
int y;
public:
OPairType (int=0, int=0);
int getX() const;
int getY() const;
void setX(int);
void setY(int);
void setValues(int, int);
friend OPairType operator + (OPairType, OPairType);
friend OPairType operator - (OPairType, OPairType);
friend bool operator == (OPairType, OPairType);
friend bool operator != (OPairType, OPairType);
friend std::ostream& operator << (std::ostream&, OPairType);
And here is the .cpp code:

#include "OPairType.h"
#include <iostream>

OPairType::OPairType (int x, int y); //error occurs here

int OPairType::getX() const {
return x;
}

int OPairType::getY() const {
return y;
}

void OPairType::setX(int new_x) {
x = new_x;
}

void OPairType::setY(int new_y) {
y = new_y;
}

void OPairType::setValues (int new_x, int new_y){
x = new_x;
y = new_y;
}

OPairType operator + (OPairType lh, OPairType rh){
OPairType answer;

answer.x = lh.x + rh.x;
answer.y = lh.y + rh.y;

return answer;
}

OPairType operator - (OPairType lh, OPairType rh){
OPairType answer;

answer.x = lh.x - rh.x;
answer.y = lh.y - rh.y;

return answer;
}

bool operator == (OPairType lh, OPairType rh){
return lh.x == rh.x && lh.y == rh.y;
}

bool operator != (OPairType lh, OPairType rh){
return !(lh.x == rh.x && lh.y == rh.y);
}

std::ostream& operator << (std::ostream& out, OPairType c){
out << "(" << c.x << ", " << c.y << ")";
return out;
}
Any responses at all will be appreciated. Just be fast is all I ask

sorry about the smileys, first time posting. They are supposed to be double colons "::"

It's just what the compiler says. I guess you meant to implement the constructor, but the way it's written, with the ; and no body, it looks more like a definition, and it's outside of the class definition. You have it declared inside the class. You need to provide the implementation outside.

OPairType::OPairType (int x, int y);

would this work?

OPairType::OPairType (int x, int y) {
x=y=0;
}

Edit: I've got it to compile now using the above code. Now my output is coming out wrong. I'm leaving c's ordered pair as default(0, 0) but when I use cout<<c<<endl it outputs (-2, 1991577954).

Any Ideas??

Quote:

---

Originally Posted by ldicus34

sorry about the smileys, first time posting. They are supposed to be double colons "::"

---

It is because you didn't use Code tags. Besides the "smileys" problem your code is very hard to read/understand.
Please, read the Announcement: section Information on posting

Before posting, please format your code properly and use code tags. Go Advanced, select the code and click '#'.

Code:

---

OPairType::OPairType (int x, int y); //error occurs here

---

You are trying to define a constructor with two parameters. This is a forward declaration and not a definiton. Also it isn't good practice to use paramater variables which have the same names as class variables.

I suspect the required constructor definition is

Code:

---

OPairType::OPairType (int px, int py) : x(px), y(py) {}

---

Quote:

---

Originally Posted by ldicus34

would this work?

OPairType::OPairType (int x, int y) {
x=y=0;
}

---

That line sets temporary variables x and y to 0, and does nothing else. So effectively, that constructor accomplishes nothing, even though you were able to get it to compile.

Quote:

---

Any Ideas??

---

If you posted your entire program, including the main() function, then maybe we have "ideas". However you're the one that should be responsible for debugging your own programs -- leaving it to a forum full of experienced and professional programmers to do this work would be considered cheating.

One thing:

Code:

---

bool operator == (OPairType lh, OPairType rh){
return lh.x == rh.x && lh.y == rh.y;
}

bool operator != (OPairType lh, OPairType rh){
return !(lh.x == rh.x && lh.y == rh.y);
}

---

First, those parameters should be const references. Second, the operator != could have been simply coded like this:

Code:

---

bool operator != (const OPairType& lh, const OPairType& rh)
{
    return !(lh == rh);
}

---

This is logically what operator != is supposed to mean, and that is "not equal". Since "equal" is already coded, reuse it by just sticking a "not" in front of it.

The reason to do things this way is that operator == is already coded. If operator == is later changed (made more complex for example), then operator != automatically works without any changes.

Regards,

Paul McKenzie