Compilation unit

How can I restrict a class and its methods not to be exported out of the compilation unit?

The same way I use 'static' in front of a function declaration.

Thanks!

/* file test.cpp */
#include <iostream>

using namespace std;

class A
{
public:
  int val;

  int f()
  {
    return val;
  };
};

float f2();

int main()
{
  A i;

  i.val = 3;

  cout << i.f() << ' ' << f2() << '\n';
  return 0;
}
/* End of test.cpp */
/* File test2.cpp */
class A
{
public:
  float val;

  float f()
  {
    return val;
  };
};

float f2()
{
  A v;
  v.val = 3.;

  return v.f();
}
/* End of test2.cpp */

Now compile with:

g++ -o test test.cpp test2.cpp

I think it should print "3 3", but it prints in my computer "3 nan".