C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Smart Pointer library in C++          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Allerdyce.John@gmail.com Guest Posted: Mon Jan 23, 2006 5:12 am    Post subject: Smart Pointer library in C++ I think Smart Pointer library in C++ is implemented using reference count. How does smart pointer library detect if there is a circular reference? and if yes, what does it do about it? Thank you. Back to top Luke Meyers Guest Posted: Mon Jan 23, 2006 5:37 am    Post subject: Re: Smart Pointer library in C++ [email]Allerdyce.John (AT) gmail (DOT) com[/email] wrote: Quote: I think Smart Pointer library in C++ is implemented using reference count. How does smart pointer library detect if there is a circular reference? and if yes, what does it do about it? What library are you referring to? There is no standard smart pointer library for C++. The only thing that's even close is std::auto_ptr, which does not use refcounts because it transfers ownership on copy. Maybe you're referring to boost::shared_ptr? If so, that's off-topic here, but to briefly answer your question: it doesn't detect cycles, it's up to the programmer to keep that from happening. Cycle detection would be a property of a full-scale GC system, more overhead than I'm willing to accept from a comparatively lightweight smart pointer type. If you're curious about the implementation details, just go read boost/shared_ptr.hpp. Luke Back to top Kai-Uwe Bux Guest Posted: Mon Jan 23, 2006 6:25 am    Post subject: Re: Smart Pointer library in C++ Luke Meyers wrote: Quote: Allerdyce.John (AT) gmail (DOT) com wrote: I think Smart Pointer library in C++ is implemented using reference count. How does smart pointer library detect if there is a circular reference? and if yes, what does it do about it? What library are you referring to? There is no standard smart pointer library for C++. The only thing that's even close is std::auto_ptr, which does not use refcounts because it transfers ownership on copy. Well, there is tr1::shared_ptr, formerly known as boost::shared_ptr. Quote: Maybe you're referring to boost::shared_ptr? If so, that's off-topic here [snip] I beg to differ: Boost libraries are the most canonical candidates for standardization. Thus, they are directly relevant to "planned extensions and adjustments" as mentioned in the FAQ: Only post to comp.lang.c++ if your question is about the C++ language itself. For example, C++ code design, syntax, style, rules, bugs, etc. Ultimately this means your question must be answerable by looking into the C++ language definition as determined by the ISO/ANSI C++ Standard document, and by *planned extensions and adjustments*. (Emphasis added) The fact that boost::shared_ptr now is in tr1 illustrates this point. Also, Boost libraries, which strive to be as platform independent as possible, have been by and large regarded topical on this news group for quite some time. Best Kai-Uwe Bux Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ language (comp.lang.c++) All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.