How compiler diffrentiates oridnary/member funtion w.r.t private data members

[vinothg]

Hi All,

I just wanna know how compiler diffrentiates between a ordinary function and member function. I know that compiler will secretly pass the this pointer to member functions. Eg : look at this code.

#include <iostream>
 
using namespace std;
 
class A {
int i;
public :
int k;
void set(A* a, int i){
a -> i = i; >>>> Here it is ok
} 
};
 
 
int main(){
A *a = new A;
//a -> i = i; >>>> Here is the problem.
a->set(a,100);
getchar();
}
 

Here if i access i from main() which is a private data memeber of class A then it is a error. If i do the same inside a member function then it is ok. How this kind of diffrentiation is possible ? I got a clue from this forum that it is through namespace. Can anybody explain how ???

[rhitam30111985]

set() function being a public memeber function can be accessed from the main() function... a member function can access a private data amember .. it is allowed... but ' i ' being a private data member.. cannot be accessed from the main function...

[weaknessforcats]

In any case, you do not want to access private data members in main(). It often happens that classes need to be redesigned and iof the data mamber names all scattered all over the use code, then in addittion to fixing the class you have to fix all the user code. What was a little job becomes a giant one. So big, in factr, that your boss may not let you redesign. If that happens, your application has just become a fossil.