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### 748. The is_abstract type trait is defined by reference to 10.4.

Section: 20.15.5.4 [meta.unary.prop] Status: NAD Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

I am trying to decide is a pure virtual function is a necessary as well as sufficient requirement to be classified as abstract?

For instance, is the following (non-polymorphic) type considered abstract?

>     struct abstract {
>     protected:
>      abstract(){}
>      abstract( abstract const & ) {}
>      ~abstract() {}
>     };

(Suggested that this may be NAD, with an editorial fix-up from Pete on the core wording to make clear that abstract requires a pure virtual function)

Proposed resolution:

Core has clarified that the definition abstract is adequate. Issue withdrawn by submitter. NAD.