Hi,

I found missing description. N3337 19.5.1.1 error_category:
virtual ~error_category() noexcept;

This function is nothing description.

Correct code is follow?
virtual ~error_category() noexcept = default;

Thanks,
Akira


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On 2012-03-20 07:22, Akira Takahashi wrote:
>  I found missing description. N3337 19.5.1.1 error_category:
>  virtual ~error_category() noexcept;
>
>  This function is nothing description.

I agree, because a virtual destructor is not covered by the general
statement in [functions.within.classes] p1.

>  Correct code is follow?
>  virtual ~error_category() noexcept = default;

Except for the explicit noexcept specification, yes. There is a general
normative statement in [res.on.exception.handling] p4

"Every destructor in the C++ standard library shall behave as if it had
a non-throwing exception specification."

which rules this already. This is the reason why *no* destructor
declaration in the library specification does have any noexcept
specification. Adding this suddenly at one place would make give the
impression that we have a special case here.

HTH&  Greetings from Bremen,

Daniel Kr   gler



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>  >    I found missing description. N3337 19.5.1.1 error_category:
>  >    virtual ~error_category() noexcept;
>
>  >    This function is nothing description.
>
>  I agree, because a virtual destructor is not covered by the general
>  statement in [functions.within.classes] p1.
>
>  >    Correct code is follow?
>  >    virtual ~error_category() noexcept = default;
>
>  Except for the explicit noexcept specification, yes. There is a general
>  normative statement in [res.on.exception.handling] p4
>
>  "Every destructor in the C++ standard library shall behave as if it had
>  a non-throwing exception specification."
>
>  which rules this already. This is the reason why *no* destructor
>  declaration in the library specification does have any noexcept
>  specification. Adding this suddenly at one place would make give the
>  impression that we have a special case here.
>
>  HTH&    Greetings from Bremen,
>
>  Daniel Kr   gler
>

Oh, your right.
I get new knowledge. Thanks.

Summary, should change:

virtual ~error_category() = default;

or add description:

"Effects: Destroys an object of class error_category."

Thanks,
Akira


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