https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116676
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Slightly reduced: ``` #include <utility> namespace std { auto [fet1, err1] = std::pair<const int &, int > { 1, 1 }; int t; } ``` and yes the namespace here needs to be std.