copy-constructor

I just realised that this program compiles and runs (gcc version 4.4.5 / Ubuntu): #include <iostream> using namespace std; class Test { public: // copyconstructor Test(const Test& other); }; Test::Test(const Test& other) { if (this == &other) cout << "copying myself" << endl; else cout << "copying something else" << endl; } int main(int argv, char** argc) { Test a(a); // compiles, runs and prints "copying myself" Test *b = new Test(*b); // compiles, runs and prints "copying something else" } I wonder why on earth this even compiles. I assume that (just as in Java) arguments are evaluated

I have the following code to test out my understanding of basic pointers in C++: // Integer.cpp #include "Integer.h" Integer::Integer() { value = new int; *value = 0; } Integer::Integer( int intVal ) { value = new int; *value = intVal; } Integer::~Integer() { delete value; } Integer::Integer(const Integer &rhInt) { value = new int; *value = *rhInt.value; } int Integer::getInteger() const { return *value; } void Integer::setInteger( int newInteger ) { *value = newInteger; } Integer& Integer::operator=( const Integer& rhInt ) { *value = *rhInt.value; return *this; } // IntegerTest.cpp #include

I know that if you leave a member out of an initialization list in a no-arg constructor, the default constructor of that member will be called. Do copy constructors likewise call the copy constructor of the members, or do they also call the default constructor? class myClass { private: someClass a; someOtherClass b; public: myClass() : a(DEFAULT_A) {} //implied is b() myClass(const myClass& mc) : a(mc.a) {} //implied is b(mc.b)??? or is it b()? } Explicitly-defined copy constructors do not call copy constructors for the members. When you enter the body of a constructor, every member of that

I would like to make copy of SubClass object in BaseClass constructor. I need that the following code execute correctly. class BaseClass{ BaseClass() {} BaseClass(BaseClass base) { //TODO: how to implement? } } class SubClass extends BaseClass { SubClass() {} } public class Test { public static void main(String[] args) { BaseClass sub = new SubClass(); BaseClass subCopy = new BaseClass(sub); if (subCopy instanceof SubClass) { // need to be true } } } Is it even possible? If yes how can I do it? Else how can I get similar effect? qqilihq It's not possible. A constructor of class A gives you an

Does a copy of an object with object instance variables get the same instance variable as the original object? if so, I was wondering if the original and copy objects are referencing to the same instance variables. Unlike C++, Java does not provide copy constructors automatically. There is therefore no general answer to any question about the behavior of copy constructors, as Java places no restrictions on their behavior. Nevertheless, every object, however initialized, has its own instance variables. These are not shared with any other object; they can be "the same" as another object's only