From: Maxim Yegorushkin (e-maxim_at_[hidden])
Date: 2004-12-19 22:39:32
Dirk Gregorius wrote:
> I saw some code that declared the copy operations private in the base
> class Interface
> virtual void f() = 0;
> Interface( const Interface& );
> Interface& operator=( const Interface& );
> So in order to gain maximum style and correctness points I need to make
> classes ( Interface and Implementation ) noncopyable?
Only a base class. This prevents a compiler from generating copy ctor and
assignment in its successors.
> Why is this possible?
Because a compiler generates copy ctor and assignment when nothing
> Does it make sense to dereference an interface?
It does make sense, since there can be functions taking an interface by
reference. But dereferencing and assigning it does not.
> Interface* p1 = make_interface();
> Interface* p2 = make_interface();
> *p1 = *p2;
> Or does your example only work with auto/smart pointers?
For plain pointers also.
Some say noncopyable interfaces may save from errors, though making them
noncopyable I've never encountered that kind of errors.
-- Maxim Yegorushkin
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