Hi, I'm working on a factory generator tool and I would like to support types with initializer-list constructors, typically containers. There are several possibilities how to do this, but the otherwise most straightforward and generic way, requires non-standard construction of std::initializer_list<T> instances. I have the following working implementation for GCC (a complete, very simplified example showing the usage that can be compiled with g++ 4.5 with --std=c++0x is in the attachment): template <typename Element> class initializer_list_holder { private: typename std::initializer_list<Element>::iterator data; typename std::initializer_list<Element>::size_type size; std::vector<Element> elems; void init(void) { data = elems.data(); size = elems.size(); } public: initializer_list_holder(std::vector<Element>&& tmp) : elems(std::move(tmp)) { init(); } template <typename StdRange> initializer_list_holder(const StdRange& src) : elems(src.begin(), src.end()) { init(); } operator std::initializer_list<Element>() const { return reinterpret_cast< std::initializer_list<Element> const & >(*this); } }; The template above stores the elements to be traversed by the initializer-list's iterators in a vector and depends on the GCC's implementation of the initializer_list. The plan is to do something similar for other implementations of initializer_list by other compilers and switch between them via the preprocessor. (Yes, I know that vector<T>::data() is a non-standard extension, and on platforms where it is not available the array of elements would be managed directly by the initializer_list_holder) My questions are: Is this is good idea ? Do you foresee some reason for any compiler to use another implementation of std::initializer_list, besides the "obvious" listed in n2672 (pair of pointers / pointer + size), that wouldn't work with the reinterpret_cast in the conversion operator ? Should I look at the other possibilities to implement the factory? TIA for your insights. Best, Matus