[SOLVED] CS #include

#include
using namespace std;

class C {
public:
C() {cout << “C::C();” << endl;};C(int) { cout << “C::C(int);” << endl; };C(C&) { cout << “C::C(C);” << endl; }};void pass_by_value(C val_c) {cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “= pass_by_value ” << endl;cout << “= address where val_c is stored: ” << &val_c << endl << endl;cout << “= = = = = = = = = = = = = = = = =” << endl;}void pass_by_reference(C& ref_c) {cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “= pass_by_reference ” << endl;cout << “= address of object that ref_c refers to: ” << &ref_c << endl << endl;cout << “= = = = = = = = = = = = = = = = =” << endl;}void pass_by_pointer(C* ptr_c) {cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “= pass_by_pointer ” << endl;cout << “= address of object pointed to by ptr_c: ” << ptr_c << endl << endl;cout << “= = = = = = = = = = = = = = = = =” << endl;}C pass_and_return_by_value(C val_c) {cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “address where val_c is stored: ” << &val_c << endl << endl;// returning by value returns a copy of the local object (copied using the copy constructor). return val_c; }C* pass_and_return_by_pointer(C* ptr_c) {cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “address of object pointed to by ptr_c: ” << ptr_c << endl << endl;cout << “= = = = = = = = = = = = = = = = =” << endl;// Here we return a pointer to the object. // // Returning a pointer the original object is not really useful (though it avoids making a copy of the object)// Really useful if we want to receive an object, do some processing usingit, // and return a new object created locally that resides on the heap, // or sometimes receive a null pointer and return a pointer to newly created object.// // if (ptr_c) {// process and change the passed object// } else {// do some processing and create a new pointer to a C// } return ptr_c; }C& pass_and_return_by_reference(C& ref_c) {cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “= address of object that ref_c refers to: ” << &ref_c << endl << endl;cout << “= = = = = = = = = = = = = = = = =” << endl;// here we return the original reference// // Use this if you want the calling function to use the function call as a value part of an expression. // The most famous example of pass-and-return-by reference is the implementation // of stream extraction/insertion operators (<>).
//
// Limitation: as a reference cannot be made to point to a new object or to be null,
// passing/returning by pointer is often the appropriate solution.
return ref_c;
}
int main() {
cout << “= = = = = = = = = = = = = = = = =” << endl;C c;cout << “= = = = = = = = = = = = = = = = =” << endl;cout << “address where c is stored : ” << &c << endl << endl;cout << “passing by value” << endl;pass_by_value(c);cout << “passing by reference” << endl;pass_by_reference(c);cout << “passing by pointer” << endl;pass_by_pointer(&c);cout << “passing/returning by value” << endl;c = pass_and_return_by_value(c);cout << “passing/returning by reference” << endl;c = pass_and_return_by_reference(c);cout << “passing/returning by pointer” << endl;c = *pass_and_return_by_pointer(&c);return 0;}