A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.
Document number: N4048
by Vicente J. Botet Escribá
This paper complements "N3784 Improvements to
std::future<T>and Related APIs"  with more future observers and factories. It is a revision of N3865  making coherent the expected proposal  and this one.