HI @Hans. thanks a lot. just fyi, on another thread at: http://lists.gnu.org/archive/html/bug-bison/2016-08/msg00006.html
it seems I could use std::unique_ptr as the semantic value , but need one hack - return *new (yyas_<T> ()) T (t); + return *new (yyas_<T> ()) T (std::move((T&)t)); min On Thu, Aug 18, 2016 at 4:39 PM, Hans Åberg <haber...@telia.com> wrote: > > > On 18 Aug 2016, at 21:07, Min Wang <mingew...@gmail.com> wrote: > > > Could you explain more on "reference count” ? > > One adds an integer variable for each object, keeping track how many other > objects referencing it, cf. [1]. Might be used in a runtime environment > where one cannot risk hitting GC time, but is tricky to implement by hand, > and one limitation is that circular reference are not removed. > > The programming language Swift has that builtin [2-3]. > > > do you mean std::shared_ptr? > > Yes, this class of C++11 and later provides it, so you might try it, cf. > [4]. > > > 1. https://en.wikipedia.org/wiki/Reference_counting > 2. https://en.wikipedia.org/wiki/Swift_(programming_language) > 3. https://developer.apple.com/library/ios/documentation/ > Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting. > html > 4. https://en.wikipedia.org/wiki/Smart_pointer#shared_ptr_and_weak_ptr > > > > -- http://www.comrite.com _______________________________________________ help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
