http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54388
--- Comment #3 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2012-08-28 13:43:42 UTC --- (In reply to comment #2) > The fix is to remove the constexpr from array::at, which isn't required by the > standard anyway: It's not required, but I would like to encourage you to keep it if possible, because otherwise it would like as if the constexpr extension paper http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3304.html would have no implementation experience. Here is my suggested replacement instead (based on comma operator semantics): Replace return __n < _Nm ? _M_instance[__n] : throw out_of_range(__N("array::at")); by return __n < _Nm ? 0 : throw out_of_range(__N("array::at")), _M_instance[__n]; This should work, because the right argument of comma operator determines type and value category
