error:invalid use of member

following errors i am getting on execution. Related part of code i am presenting.

Quote:

---

g++ -c -pipe -g -Wall -W -D_REENTRANT -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/local/Trolltech/Qt-4.1.2/mkspecs/linux-g++ -I. -I/usr/local/Trolltech/Qt-4.1.2/include/QtCore -I/usr/local/Trolltech/Qt-4.1.2/include/QtNetwork -I/usr/local/Trolltech/Qt-4.1.2/include/QtGui -I/usr/local/Trolltech/Qt-4.1.2/include -I. -I. -o client.o client.cpp
client.cpp: In member function ‘void Client::calculating()’:
client.cpp:112: error: invalid use of member (did you forget the ‘&’ ?)
client.cpp:113: error: invalid use of member (did you forget the ‘&’ ?)
client.cpp:125: error: invalid use of member (did you forget the ‘&’ ?)
client.cpp:128: error: no matching function for call to ‘Client::startSending(<unknown type>, <unknown type>)’
client.h:53: note: candidates are: void Client::startSending(int, int)
client.cpp:129: error: invalid use of member (did you forget the ‘&’ ?)
client.cpp:137: error: invalid use of member (did you forget the ‘&’ ?)
client.cpp:142: error: invalid use of member (did you forget the ‘&’ ?)
make: *** [client.o] Error 1

---

swap is not a member of class.

Code:

---

void swap(int *a,int *b)
 {
	int *t;
	*t = *a;
	*a = *b;
	*b = *t;
 
 }
int x,y,x1=0, y10=0 ,x2=100,y2=100,e,dy,dx,absolute; //declared at global scope, not member of class
 
void Client::calculating()
{
 
	if(x1>x2)
	{
		swap(&x1,&x2);
		swap(&y10,&y2);
	}
	x = x1;
	y = y10;
 
	if((y2-y10)<0)
	absolute = -1;
	else
	absolute = 1;
 
	dy = absolute*(y2-y10);
	dx = x2-x1;
 
	//usleep(1000*1000*1);
	e = (2*dy)-dx;
	while( x < x2)
	{
 
		emit startSending(x,y);
		x = x+1;
 
		if(e<0)
		e = e+(2*dy);
 
		else
		if (y10>y2)
		{
		y = y-1;
		e = e+(2*dy)-(2*dx);
		}
		else
		{
		y = y+1;
		e = e+(2*dy)-(2*dx);
		}
 
 
	}
 
 
 
}

---

In swap, all references to t should be without the *. E.g. t = *a; *a = *b; *b = t;

Is this Client class a widget?

yes , it inherits QDialog.
But wheni made these global variables x,x1,y10,y2 etc. a member of client , allthings went well, why i couldn't understand

Quote:

---

Originally Posted by quickNitin

yes , it inherits QDialog.
But wheni made these global variables x,x1,y10,y2 etc. a member of client , allthings went well, why i couldn't understand

---

Because x and y are also names of QDialog methods, so those global variables weren't visible. Usually usage of global variables is a bad idea, but in that case you could access using the scope operator.

Like this:

Code:

---

::x = 10 + ::y;

---