multiple-inheritance

I show an example of what I mean which, is easier. Imagine the generic type C means Color type: So for visual simplification assume C is C extends Color interface Screen { <C> Background<C> render(Plane<C> plane); } interface MonochromeScreen<C> extends Screen{ @Override Background<C> render(Plane<C> plane); } This would throw a name clash compilation error explaining that both have the same type erasure but are not overridable. But I cannot understand why we could not simply allow overriding the signature as long as it is more restrictive. I mean, after all, the only difference is the scope

I have the following hierarchy of COM interfaces and a class implementing them: interface IX : public IUnknown{}; interface IY : public IUnknown{}; class CA: public IX, public IY{}; Here class CA effectively inherits from IUnknown twice. We know there are two vtable pointers in class CA - one is pointed to IX and another is pointed to IY . So IUnknown stored in the IX subobject is different from IUnknown stored in the IY subobject. Yet when we call IX::QueryInterface() or IY::QueryInterface() on the same object and query IUnknown we get identical IUnknown* pointers. Why does it happen?

When using multiple inheritance C++ has to maintain several vtables which leads to having "several views" of common base classes. Here's a code snippet: #include "stdafx.h" #include <Windows.h> void dumpPointer( void* pointer ) { __int64 thisPointer = reinterpret_cast<__int64>( pointer ); char buffer[100]; _i64toa( thisPointer, buffer, 10 ); OutputDebugStringA( buffer ); OutputDebugStringA( "\n" ); } class ICommonBase { public: virtual void Common() = 0 {} }; class IDerived1 : public ICommonBase { }; class IDerived2 : public ICommonBase { }; class CClass : public IDerived1, public IDerived2 {

I have a class Journey which I want to make a superclass and another class plannedjourney. The plannedjourney class extends JFrame since it contains forms..However I also want this class to extends Journey.. Is there a possible way to do this? Don't mix models and views. If you keep both domains clearly separated, then you won't be in need of multiple inheritance (this time). You have one model class for journeys and a viewer for such journeys. The viewer should subclass Component and be displayed (somewhere) in your window (a JFrame instance). This viewer takes one journey object and presents

What I know is that size of empty class is 1 just to conform to the standard that does not allow objects (and classes thereof) of size to be 0. Here, I am getting size of a derived class D as 2. Why behavior is different in this case given that there is no data member or virtual pointer inherited from class B and C to D? #include<iostream> using namespace std; class A {}; class B : public A {}; class C : public A {}; class D : public B, public C {}; int main() { cout<<"Size of D is: "<<sizeof(D)<<endl; return 0; } To me it seems that whether or not the empty base optimization can be applied

Given this code: template < int I > class Foo { public: int v; Foo() { v = I; } virtual ~Foo() {} }; class Bar : public Foo<0>, public Foo<3> { public: template < int I > int getValue() { return Foo<I>::v; } }; int main() { Bar b; cout << b.getValue<0>() << endl; // prints 0 cout << b.getValue<3>() << endl; // prints 3 cout << b.getValue<4>() << endl; // compiler error return 0; } Is it possible to iterate over all Foo<i> classes from which Bar inherits? We can assume that i is between 0 and some maximum N . In pseudocode: for ( int i = 0; i < N; i++ ) { if ( Bar inherits from `Foo<i>` ) {