https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82647
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- >If I additionally include <tuple>, which should be unnecessary, this compiles. I don't have the final C++17 spec but the draft (dated March 21, 2017, doc N4659) says tuple_size_v is defined in tuple and no other header file.
