https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65978
Bug ID: 65978 Summary: missing constexpr on std::forward_as_tuple and std::tie (LWG issues 2275 and 2301) Product: gcc Version: 5.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: rhalbersma at gmail dot com Target Milestone: --- Neither libstdc++ 5.1.0 nor the trunk version implement LWG defect reports 2275 and 2301 that make std::tuple utilities std::forward_as_tuple and std::tie constexpr http://wg21.cmeerw.net/lwg/issue2275 http://wg21.cmeerw.net/lwg/issue2301 Both of these have been implemented in libc++ for a while now: http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20131007/090369.html http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20140224/099936.html Since both resolutions only require C++11 style constexpr support, they could also be backported to earlier versions in -std=c++1y mode.