Joaqumn M Lspez Muqoz wrote:
push_back() can also throw from the allocator if it runs out of memory, so you really need some proper clenaup regardless of the guarantees made by copying ops. Dave's suggestion of using RAII is probably the most elegant way to deal with the situation: in my experience, however, this sort of scope guards perform worse than a try{}catch(...){}. Your mileage may vary.
Anything wrong with the following? // reserve space on stack for an object of type T without actually // construction such an object template< typename T > struct stack_allocate { T * address() { return static_cast<T*>(storage_.address()); } T & reference() { return * address(); } private: aligned_storage< sizeof(T), alignment_of<T>::value > storage_; }; // construct element on the stack template<class Archive, class T> struct stack_construct : public stack_allocate<T> { stack_construct(Archive & ar){ load_construct_data(ar, address(), 0U); } ~stack_construct(){ address()->~T(); // undo load_construct_data above } }; // sequential container input template<class Archive, class Container> struct archive_input_seq { // archive_input_seq(){} inline void operator()(Archive &ar, Container &s) { typedef BOOST_DEDUCED_TYPENAME Container::value_type type; stack_construct<Archive, type> t(ar); ar >> make_nvp("item", t.reference()); s.push_back(t.reference()); } };