Linked List Bubble Sort?

[pkjm17]

How is it possible to do a bubble sort for a linked list? I want to be able to sort the data in ascending order. I think my algorithm for my Sort method is incorrect, as I get the following error over "temp->getOneNumber()": Expression must be a modifiable lvalue. Doesn't it return a number though? Here is my whole program...

#include <iostream>
#include <cstdlib>
using namespace std;

class Node {
public:
Node* getNextPointer();
void putNextPointer(Node* x);
Node* putOneNumber(Node* x, int noun);
int getOneNumber();
int setOneNumber(int number);
private:
int n;
Node* nextPtr;
};

class BagList {
public:
BagList ();
bool putNumber(int n);
void display();
void sort();
private:
Node* ListPointer;
};

// Node Class Methods
Node* Node::getNextPointer (){
return nextPtr;}

void Node::putNextPointer (Node* x){
this->nextPtr = x;}

Node* Node::putOneNumber (Node* x, int number) {
Node* temp = NULL;
if ((temp = new Node())) {
temp->nextPtr = x;
temp->n = number;}
return temp;}

int Node::getOneNumber() {
return n;}

int Node::setOneNumber(int number)
{n = number;
return n;}

// BagList Class Methods
BagList::BagList () {ListPointer = NULL;}

void BagList::display(){
Node *temp;
for(temp = ListPointer; temp!= NULL; temp = temp->getNextPointer())
cout<<temp->getOneNumber() <<" ";
cout<<endl;
}

void BagList::sort(){
Node *temp;
int temp1;
for(bool didSwap = true; didSwap; ){
didSwap = false;

for(temp = ListPointer; temp!= NULL; temp = temp->getNextPointer())
{

if (temp->getOneNumber() > temp->getNextPointer()->getOneNumber())
{

temp1 = temp->getOneNumber();
temp->getOneNumber() = temp->setOneNumber(temp->getNextPointer()->getOneNumber());
temp->setOneNumber( temp->getNextPointer()->getOneNumber() = temp1;
didSwap = true;
}
}
}
}

bool BagList::putNumber (int n) {
bool x = false;
Node* temp1;
Node A;
temp1 = A.putOneNumber (ListPointer, n);
if (temp1 != NULL)
{ ListPointer = temp1;
x =true;
}
return x;}

int main () {
BagList A;
int num;
cout << "Enter 10 numbers: ";
for(int i=0; i<10; i++)
{
cin>>num;
if (!cin.eof()&&cin.good())
A.putNumber(num);
}
cout<<endl <<endl;
A.display(); //display numbers
A.sort(); //sort the numbers
A.display(); //display them in ascending order

system("pause");
return 0;
}