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### 1260. `is_constructible<int*,void*>` reports true

Section: 20.15.5.4 [meta.unary.prop] Status: Resolved Submitter: Peter Dimov Opened: 2009-11-07 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

The specification of `is_constructible<T,Args...>` in N3000 uses

>     static_cast<T>(create<Args>()...)

for the one-argument case, but `static_cast` also permits unwanted conversions such as `void*` to `T*` and `Base*` to `Derived*`.

[ Post-Rapperswil: ]

> Moved to NAD Editorial Resolved, this issue is addressed by paper n3047

Proposed resolution:

Change 20.15.5.4 [meta.unary.prop], p6:

> the predicate condition for a template specialization `is_constructible<T, Args>` shall be satisfied, if and only if the following expression CE variable definition would be well-formed:

> - if `sizeof...(Args) == 0 1`, the expression:

>   >     static_cast<T>(create<Args>()...)
>   >     T t;

> - otherwise the expression:

>   >     T t(create<Args>()...);