Nonstatic member as a default argument of a nonstatic member function

Question

struct X
{
   X():mem(42){}
   void f(int param = mem) //ERROR
   {
      //do something
   }
private: 
   int mem;
};

Can anyone give me just one

Answer 1

As all the other answers just discuss the problem, I thought I would post a solution.

As used in other languages without default arguments (Eg C# pre 4.0)

Simply use overloading to provide the same result:

struct X
{
   X():mem(42){}
   void f(int param)
   {
      //do something
   }
   void f()
   {
      f(mem);
   }
private: 
   int mem;
};