multiple-inheritance

Say we have a class inheriting from two base classes (multiple inheritance). Base class A is abstract, declaring a pure virtual function foo , the other base class B declares and implements a function foo of the very same signature. struct A { virtual void foo(int i) = 0; }; struct B { virtual void foo(int i) {} }; struct C : public A, public B {}; I want to use the implementation of foo from base class B in my derived class C . However, if I do not implement the function foo a second time in my derived class C , I cannot instantiate any object of it (it remains abstract). Virtual inheritance

class A { protected: string word; }; class B { protected: string word; }; class Derived: public A, public B { }; How would the accessibility of the variable word be affected in Derived ? How would I resolve it? It will be ambiguous, and you'll get a compilation error saying that. You'll need to use the right scope to use it: class Derived: public A, public B { Derived() { A::word = "A!"; B::word = "B!!"; } }; You can use the using keyword to tell the compiler which version to use: class Derived : public A, public B { protected: using A::word; }; This tells the compiler that the Derived class

I face the well known "dreaded" diamond situation : A / \ B1 B2 \ / C | D The class A has, say the constructor A::A(int i) . I also want to forbid a default instantiation of a A so I declare the default constructor of A as private . The classes B1 and B2 are virtually derived from A and have some constructors and a protected default constructor. [edit] The constructors of B1 and B2 don't call the default constructor of A . [reedit] The default constructors of B1 and B2 don't call the default constructor of A either. [reedit] [edit] The class C is an abstract class and has some constructors

Is it possible to create a class that inherits from multiple instances of namedtuple , or create something to the same effect (having an immutable type that combines the fields of the base types)? I haven't found a way to do so. This example illustrates the problem: >>> class Test(namedtuple('One', 'foo'), namedtuple('Two', 'bar')): >>> pass >>> t = Test(1, 2) TypeError: __new__() takes 2 positional arguments but 3 were given >>> t = Test(1) >>> t.foo 1 >>> t.bar 1 The problem seems to be that namedtuple does not use super to initialize its base class, as can be seen when creating one: >>>

I'm not very well aquainted with javascript inheritance, and I'm trying to make one object inherit from another, and define its own methods: function Foo() {} Foo.prototype = { getColor: function () {return this.color;}, }; function FooB() {} FooB.prototype = new Foo(); FooB.prototype = { /* other methods here */ }; var x = new FooB().getColor(); However, the second one overwrites the first one( FooB.prototype = new Foo() is cancelled out ). Is there any way to fix this problem, or am I going in the wrong direction? Thanks in advance, sorry for any bad terminology. Each object can only have

I'd like to create a new class that inherits two subclasses of QWidget. I know multi-inheritance isn't possible in pyqt, but how could I manage to have the properties of both parent classes in one subclass? What I wish I could do is as follows: class A(QWidget): def __init__(self, widget, parent=None): widget.destroyed.connect(self.destroy_handler) @pyqtSlot() def destroy_handler(self): pass class B (A, QStatusBar): def __init__(self, widget, parent=None): A.__init__(self, widget) QStatusBar.__init__(self, parent) @pyqtSlot() def destroyed_handler(self): print("Destroyed") I finally found how