Copy constructor - script per MetaTrader 5

/****************************************************************/
void ClassExample()
  {
   Print(__FUNCTION__);
   A a1;
   A a2=Fa(); //object receive from function
   a1.Work();
   a1.Report(); //1 1 1 1
   a2.Report(); //3 3 3 3
   /*CONTINUE USE OBJECT FROM FUNCTION*/
   a2.Work();
   a2.Report(); //4 4 4 4
   return;
  }
/***************************************************************
   PARTS OF CLASS A*/
struct C {int mx; C():mx(0) {}};
class D {public:int mx; D():mx(0) {} D(D &d):mx(d.mx) {}};
/****************************************************************/
class A
  {
protected:
   int               mx;   //simple
   int               ma[]; //array
   C                 mc;   //struct
   D                 d;    //class
public:
   /*COPY CONSTRUCTOR*/
                     A(A &a):mx(a.mx),d(a.d) {ArrayCopy(ma,a.ma); mc=a.mc;}
   /*EXPLICIT DEFAULT CONSTRUCTOR*/
                     A():mx(0) {}
   /*METHODS*/
   void              Work() {mx++; ArrayResize(ma,mx); mc.mx=mx; d.mx=mx;}
   void              Report() {Print(mx," ",ArraySize(ma)," ",mc.mx," ",d.mx);}
  };
/****************************************************************/
A Fa()
  {
   A a;
   for(int i=0; i<3; i++)
     {a.Work();} //a lot of work
   return a; //class object return
  }
/**/

/****************************************************************/
void StructExample()
  {
   Print(__FUNCTION__);
   B b1;
   B b2=Fb(); //struct receive from function
   b1.mx++;
   /**/
   Print(b1.mx," ",ArraySize(b1.ma)); //  1 0
   Print(b2.mx," ",ArraySize(b2.ma)); // 10 9
   return;
  }
/****************************************************************/
struct B
  {
   int               mx;
   int               ma[];
                     B():mx(0) {} //constructor, not needed formally
  };
/****************************************************************/
B Fb()
  {
   B b;
   for(int i=0; i<10; i++)
     {b.mx++; ArrayResize(b.ma,i);} //work hard
   return b; //struct return
  }
/**/