http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51453
Bug #: 51453 Summary: Feature request: Implement Empty Base Optimization in std::tuple Classification: Unclassified Product: gcc Version: 4.6.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: naso...@hotmail.com Is it possible to implement empty base optimization on std::tuple, so that tuples with member free elements have no memory footprint? struct _Tuple_impl<_Idx> { ... protected: short dummy[0]; // NEW void _M_swap_impl(_Tuple_impl&) { /* no-op */ } }; simple test: #include <tuple> ... class empty { short d[0]; }; std::tuple<empty, empty, empty> a; std::cout << sizeof(a) << std::endl; // 2 without tuple ebo (current), and 0 with tuple ebo ... Best, Nasos