# Standards efforts

A `variant` type is on planned for inclusion in the C++ Standard, probably in
C++17. Current working papers are (list extracted from [2015 working group
papers](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/)):

* 2015-09-28: Variant design review. [P0086R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0086r0.pdf)
* 2015-09-28: Variant: a type-safe union without undefined behavior (v2) [P0087R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0087r0.pdf)
* 2015-09-27: Variant: a type-safe union that is rarely invalid (v5) [P0088R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0088r0.pdf)
* 2015-09-24: Simply a Strong Variant [P0093R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0093r0.html)
* 2015-09-24: Simply a Basic Variant [P0094R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0094r0.html)
* 2015-09-24: The Case for a Language Based Variant [P0096R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0095r0.html)
* 2015-09-25: Implementing the strong guarantee for variant<> assignment [P0110R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0110r0.html)
* 2015-09-24: Homogeneous interface for variant, any and optional (Revision 1) [P0032R1](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0032r1.pdf)

Last state can be seen from
[The Variant Saga: A happy ending?](https://isocpp.org/blog/2015/11/the-variant-saga-a-happy-ending).

The `optional` type is also on the way into the standard.  The papers are:
* 2013-10-03: A proposal to add a utility class to represent optional objects (Revision 5) [N3793](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3793.html)
* 2014-01-18: Working Draft, Technical Specification on C++ Extensions for Library Fundamentals [N3848](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3848.html)

## Older Papers

* Older working drafts are: N4218 (rev 1), N4516 (rev 2), N4450 (rev 3), and [N4542](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4542.pdf) (rev 4). They have been split into P0086 (general design discussions) and P0087 and P0088 (containing two competing? specs).
* 2015-07-28: Variant: Discriminated Union with Value Semantics [P0080R0](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0080r0.pdf) An alternative proposal to N4542.