https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79433
--- Comment #23 from Jonathan Wakely <redi at gcc dot gnu.org> --- No, because after discussion with the feature-test study group I don't want to rely on GCC-specific magic. Instead I think it would be better for headers to do: #if __cplusplus >= 201402L #define __cpp_lib_some_feature YYYYMM ... #endif That would mean including the header doesn't give an error, but you need to test for both the header and a feature-test macro to know if the feature is really available. i.e. existence of a header doesn't imply anything except that the header can be included without error. This needs a proposal to the study group and a change to SD-6 (currently detection of many features only uses __has_include and there's no macro that can be tested) and then changes to GCC to remove the #error directives (so we allow inclusion, but define nothing when included with the wrong -std mode). None of that has been decided on yet, so it's not possible to say if some hypothetical idea would be backported to gcc-7-branch. There's nothing to backport yet. (N.B. C++14 added one new header, <shared_mutex>)
