On 02/09/2017 11:59 PM, Jonathan Wakely wrote: > It's become apparent that the feature-test recommendations for > features such as std::string_view, std::variant and std::optional are > not sufficient. > > SD-6 says that to check for std::variant you should use > __has_include(<variant>).
My gut reaction to this issue is "can't we make __has_include return false if #including the header doesn't actually provide the facility"? (I would also be happy if "#include <variant>" would simply be an error in older modes, although I do agree the gcc error message is helpful.) Jens _______________________________________________ Features mailing list [email protected] http://www.open-std.org/mailman/listinfo/features
