Here is one option that will work in MQL.
The technique is called 'copy constructor'. Make sure that all fields are copied, including complex data types, recursively.
Please refer to the example code below, you will figure out how it works.
/****************************************************************/ 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 } /**/
Want to return a structure?
Structures can be normally updated with function as parameters sent by reference.
If you wish to RETURN a struct with function, it is also possible, but unlike classes, structs do not require an explicit copy constructor.
/****************************************************************/ 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 } /**/
