namespace factor { template <typename T> cell tag(T *value) { return RETAG(value,tag_for(T::type_number)); } inline static cell tag_dynamic(object *value) { return RETAG(value,tag_for(value->h.hi_tag())); } template <typename T> struct tagged { cell value_; cell value() const { return value_; } T *untagged() const { return (T *)(UNTAG(value_)); } cell type() const { cell tag = TAG(value_); if(tag == OBJECT_TYPE) return untagged()->h.hi_tag(); else return tag; } bool type_p(cell type_) const { return type() == type_; } T *untag_check() const { if(T::type_number != TYPE_COUNT && !type_p(T::type_number)) type_error(T::type_number,value_); return untagged(); } explicit tagged(cell tagged) : value_(tagged) { #ifdef FACTOR_DEBUG untag_check(); #endif } explicit tagged(T *untagged) : value_(factor::tag(untagged)) { #ifdef FACTOR_DEBUG untag_check(); #endif } T *operator->() const { return untagged(); } cell *operator&() const { return &value_; } const tagged<T>& operator=(const T *x) { value_ = tag(x); return *this; } const tagged<T>& operator=(const cell &x) { value_ = x; return *this; } bool operator==(const tagged<T> &x) { return value_ == x.value_; } bool operator!=(const tagged<T> &x) { return value_ != x.value_; } template<typename X> tagged<X> as() { return tagged<X>(value_); } }; template <typename T> T *untag_check(cell value) { return tagged<T>(value).untag_check(); } template <typename T> T *untag(cell value) { return tagged<T>(value).untagged(); } }