Extensible Name Plans

Question

Thanks to C ++ 11, we have extended and strongly typed Enums.
But are there any plans for this extension?

Something like that:

enum class OneTwoThree : char {one=1, two=2, three=3}; enum class Four : char {four=4} extends OneTwoThree; 

Answer 1

This is not true.

Nothing in C ++ happens without paper. Conveniently, you can browse all documents on the Internet here and follow along with a more informal discussion in the language evolution study groups on official forums (the Future Suggestions group is likely to be interesting for making changes to the listings).

For papers, a quick search for names for papers before 2011 reveals the following subject:

• (N4266) Attributes for namespaces and enumerations - this applies to applying attribute qualifiers to declarations of an enumeration or namespace.
• (N4113) Types of reflection for classes, unions, and Enumerations - a number of type attributes are proposed here for checking the time of enumeration of lists at compilation time, as well as the names and values ​​of enumeration elements.
• (N3815) Querying the properties of an enumerator list is another suggestion for efficiently implementing the same function as N4113.
• (P0138R0) Building rules for enumeration class values - here we discuss the conversion rules associated with creating stronger types of "renamed integer".

None of these documents include mechanisms for adding values ​​to existing enumerations. Similarly, a cursory search for "enum" in the Future Suggestions group yields a bunch of items, none of which are related to adding new values ​​to an enumeration somewhere other than the original definition of an enumeration.

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Several attempts have been made to implement such functionality without libraries or languages; fooobar.com/questions/92210 / ... and may be useful to you.