Re: Merits of re-dispatching

[Hyman Rosen <hyrosen@mail.com>]

Dmitry A. Kazakov wrote:
> My interpretation was that if C++ dispatches then it treats the type
> as class wide,, otherwise as specific. Then the  object is always
> treated as specific in all calls from destructor. So what? Maybe it is
> hard to simulate, but well possible to explain.

I don't know what it is you think that C++ does, but in fact, all calls
to virtual methods in C++ are dispatching, unless you ask for a specifc
version using the pointer->CLASS::FUNCTION() notation. In constructors
and destructors, the type of the object is the type whose constructor
or destructor is running, and that is the type used for dispatching.

If the compiler can deduce the actual type of an object in a dispatching
call, it is of course free to call the proper method directly, and it
may be the case that such deduction is easier in a constructor or
destructor, but that is completely irrelevant to understanding what is
happening from the language viewpoint.

You may persist in maintaining your incorrect mental model of what is
going on, but the only effect will be to lead you astray in complicated
caes.