Hi, is there any reason for missing in_place_factory without arguments? I would like to write optional<my_class> mc(in_place()); I've wrote the code for this. But I can't modify the macro hell in "in_place_factory.hpp". Regards, Vaclav class in_place_factory0: public in_place_factory_base { public: in_place_factory0() {} template<class T> void apply(void* address) const { new(address) T(); } }; in_place_factory0 in_place() { return in_place_factory0(); }