__rw_is_scalar or is_scalar need to take std::nullptr_t into account

• Key: STDCXX-979
• Type: Bug
• Status: Open
• Priority: Major
• Assignee: Unassigned
• Reporter: Travis Vitek
• Component/s: TR1.4 - Metaprogramming and Type Traits
• Affects Version/s: 4.3.x
• Fix Version/s: 4.3.x

Description

The standard requires that std::is_scalar<std::nullptr_t>::value evaluate to true. The current implementation doesn't consider the std::nullptr_t type because it is not implemented yet.

Comments

[Martin Sebor]

Changed both Affects Version/s and Fix Version/s from 4.3.0 to 4.3.x since 4.3.0 hasn't been released yet. If this is fixed in 4.3.0, it doesn't make sense to file it against the same version. If not, we'll need to change Affects Version/s back to 4.3.0 and Fix Version/s to the next version after 4.3.0 that we plan to fix it in.

[Martin Sebor]

The solution should be straightforward: add a config test for nullptr_t and conditionally implement is_scalar<std::nullptr_t> when the test detects support for the type.

[Travis Vitek]

Should we not provide a definition of nullptr_t and nullptr for those systems that don't provide it natively?

[Martin Sebor]

I don't think we can make it behave the way the real deal is supposed to.