www.linux.org.ru/forum/development/8096791

Какой смысл писать самому себе?

Тупо копипаста из доки

Qt Objects: Identity vs Value

Some of the added features listed above for the Qt Object Model, require that we think of Qt Objects as identities, not values. Values are copied or assigned; identities are cloned. Cloning means to create a new identity, not an exact copy of the old one. For example, twins have different identities. They may look identical, but they have different names, different locations, and may have completely different social networks.

Then cloning an identity is a more complex operation than copying or assigning a value. We can see what this means in the Qt Object Model.

A Qt Object...

• might have a unique QObject::objectName(). If we copy a Qt Object, what name should we give the copy?
• has a location in an object hierarchy. If we copy a Qt Object, where should the copy be located?
• can be connected to other Qt Objects to emit signals to them or to receive signals emitted by them. If we copy a Qt Object, how should we transfer these connections to the copy?
• can have new properties added to it at runtime that are not declared in the C++ class. If we copy a Qt Object, should the copy include the properties that were added to the original?

For these reasons, Qt Objects should be treated as identities, not as values. Identities are cloned, not copied or assigned, and cloning an identity is a more complex operation than copying or assigning a value. Therefore, QObject and all subclasses of QObject (direct or indirect) have their copy constructor and assignment operator disabled.]

размещать много-много потомков QObject в стеке

Не нужно. man QSharedPtr / QScopedPointer.

А ещё у QObject есть волшебный аргумента конструктора parent. Почитай и про конструктор QObject.

А ещё у QObject есть волшебный аргумента конструктора parent

точно! спасибо вам

почему ... объявлены как private?

что бы запретить копирование не?

и нужна поддержка собственно сигналов\слотов, там таймеры внутри

в этом то и пролема. в кутешных мануалах всё написано.

Экземпляры QObject'ов содержат так много уникальной метаинформации (вроде уникального имени, положения в иерархии объектов и т.д.), что возможность их копирования неминуемо приводила бы к шизофрении программы или программиста. Создавай QObject'ы в куче и передавай указатели на них.