Reference to Member Variable in Function declaration in C++?

Question

I'm trying to do something like the following:

class FOO {
 void bar(int& var = m_var) {
   // ....
 }
 int m_var;
};

Why doesn't this compile? Why didn't they program this into the language? Is there any way to mimic this behavior?

Answer 1

This is not allowed because m_var is a member variable and needs to be accessed through the object.
It would compile successfully if m_var was a static member of the class.

A simple workaround is calling an overloaded function with same name or another member function through bar() (which is a member function & has access to m_var) and pass m_var as an parameter by reference.It will have the same effect you want to achieve.