Re: Inheritance of constructor/desctructor

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From	James Kuyper<jameskuyper@verizon.net>
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Subject	Re: Inheritance of constructor/desctructor
Date	Thu, 20 Dec 2012 11:49:30 -0800 (PST)
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On 12/19/2012 05:20 PM, J B wrote:
>  Hi,
>
>  I have a question about definition of inheritance (perhaps as stated in C++
>  ISO docs somewhere).
>
>  Somebody claimed that when one class is derived from another, then the base
>  class' constructors and desctructors are inherited by the derived class.
>
>  Let's consider the simplest case:
>  class Base {};
>  class Derived: public Base {};
>
>  I tend to disagree and this is my argument:
>
>  The definition of inheritance (biologic, scientific,  etc) states that it is
>  an acquisition of traits genetically transmitted from parent to offspring.
>  Well, in that case those traits in a parent are not modifiable by an offspring
>  in any way, only some of parent's "blueprint" is utilized in creation
>  of offspring's
>  "blueprint".
>
>  So, a derived class does not inherit constructors and desctructors of a base
>  class.

The C++ standard defines what it means by "inheritance"; any conflicting
concept of inheritance derived from the meanings that same word has in
biological or legal contexts should be ignored.

The C++ standard has an entire section (12.9) devoted to "Inheriting
constructors", so I think that constructors can be inherited - but what
that section is talking about is probably quite different from what
you're talking about. It's not something that automatically occurs just
because one class is derived from another. It specifically requires the
use of a using-declaration, such as

     struct D1 : B1 {
         using B1::B1;
     };

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Inheritance of constructor/desctructor J B<jb.1234abcd@googlemail.com> - 2012-12-19 14:20 -0800
  Re: Inheritance of constructor/desctructor James Kuyper<jameskuyper@verizon.net> - 2012-12-20 11:49 -0800

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