// static.cc  test various cases  note //! is about 'static'  FOUR USES !!
//            1  a static member function
//            2  a static member variable (shared by all objects of this class
//            3  local to this file
//            4  static (not on stack) variable in function - holds value
//               between calls to the function


#include <iostream>
using namespace std;

static int funct(int stuff); //! local to this file, not seen by linker     3

class Base
{
  public:
    Base(void) { B2=2; B3=3;}
    static void BF1(void);   //! definition can not go here                 1
    void BF2(void) { cout << B1 << "  " << B2 << " BF2 in Base \n";
                     B2=5; }
  private:
    static int B1; //! no =1; here  (shared by all objects of this class)   2
    int B2;
    int B3;
};

int Base::B1 = 1; //! has to be at file scope. Not in 'main' or in class    2
                  //! only one per total program, not in .h file

void Base::BF1(void) //! can not use word static in front of this
{
  cout << B1 << " BF1 static in Base \n"; //! can not use B2 or B3 in here
  B1=4;
}

static int j=3;  //! means local to this file, not visible to linker        3
static Base c;

int main(void)
{
  static int  i;   //! means not on stack, value saved from call to call   4
  Base a, b;

  a.BF2();
  a.BF1();     //! object can be used, any object, same result
  a.BF2();
  b.BF2();
  Base::BF1(); //! no object needed, but do need  Base:: syntax
  b.BF2();
  return funct(-2);  //! call to function, local to this file
}

static int funct(int stuff) //! local to this file, not seen by linker     3
{
  static int i=4;           // hold value between calls to funct           4
  j=i;
  i++;
  return stuff+3;
}

//  results, note B1 is changed in object 'a' and B1 gets changed also in 'b'
//          while B2 is changed in object 'a' and 'b' unaffected

//  1  2 BF2 in Base                                B1==1, B2==2, B2=5 in 'a' 
//  1 BF1 static in Base                            B1==1, B1=4        global
//  4  5 BF2 in Base                                B1==4, B2==5, B2=5 in 'a'
//  4  2 BF2 in Base                                B1==4, B2==2, B2=5 in 'b' 
//  4 BF1 static in Base                            B1==4, B1=4        global
//  4  5 BF2 in Base                                B1==4, B2==5, B2=5 in 'b'