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Subject: Re: [std-proposals] Make abstract classes non-deletable if no virtual destructor available
From: Vishal Oza (vickoza_at_[hidden])
Date: 2020-03-23 15:28:56


I not sure if this should be an error or the compiler should generate the
public virtual destuctor. I learn toward having the compiler generate the
public virtual destuctor.

On Mon, Mar 23, 2020 at 3:19 PM Kilian Henneberger via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> Hello,
>
> an abstract class (a class that either defines or inherits at least one
> function for which the final overrider is pure virtual)
> cannot be instantiated. However it can be destroyed. But deleting a
> Derived-object through a pointer to Base-object
> leads to undefined behaviour if the destructor of the Base-class is not
> virtual.
> There also exists a CppCoreGuideline addressing this topic:
> http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rc-dtor-virtual
>
> I want to propose that we make the attempt to delete a pointer to an
> abstract class ill-formed,
> if the abstract class does not have a (public) virtual destructor.
>
> This would turn what currently is UB into a compiler error.
> But it also might imply that code which compiles today (even if leading
> to UB), wont compile any longer after this change.
>
> I am looking forward to any feedback.
> Best regards,
> Kilian Henneberger
>
>
>
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> Std-Proposals_at_[hidden]
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>



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