C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  iterator beyond the first element          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Neelesh Bodas Guest Posted: Mon Nov 28, 2005 2:33 pm    Post subject: iterator beyond the first element C++ guarantees that there exists a valid iterator beyond the last element of a container. However, such iterator might not be written or dereferenced. This is also true for arrays - C++ gurantees that there exists one position available beyond the end of array. Does it give similar guarantee about the position before the first element - the position indicated by the iterator rbegin()? (For arrays as well as standard containers) Back to top Neelesh Bodas Guest Posted: Mon Nov 28, 2005 2:40 pm    Post subject: Re: iterator beyond the first element Neelesh Bodas wrote: Quote: the position indicated by the iterator rbegin()? (For arrays as well as standard containers) Typo. should be rend() Back to top Victor Bazarov Guest Posted: Mon Nov 28, 2005 2:41 pm    Post subject: Re: iterator beyond the first element Neelesh Bodas wrote: Quote: C++ guarantees that there exists a valid iterator beyond the last element of a container. However, such iterator might not be written or dereferenced. This is also true for arrays - C++ gurantees that there exists one position available beyond the end of array. Does it give similar guarantee about the position before the first element - the position indicated by the iterator rbegin()? (For arrays as well as standard containers) You are mistaken about at least one thing: 'rbegin()' returns an iterator that points to the _last_ element, not first. No, C++ does not guarantee the existence of "one-before-first" iterator (in your terms it would be '--begin()'). V Back to top Pete Becker Guest Posted: Mon Nov 28, 2005 2:42 pm    Post subject: Re: iterator beyond the first element Neelesh Bodas wrote: Quote: Does it give similar guarantee about the position before the first element No. Quote: the position indicated by the iterator rbegin()? rbegin() is completely different. Reverse iterators for containers use the end() and begin() iterators and index one off from the iterator's position. -- Pete Becker Dinkumware, Ltd. (http://www.dinkumware.com) Back to top Sumit Rajan Guest Posted: Mon Nov 28, 2005 2:42 pm    Post subject: Re: iterator beyond the first element "Neelesh Bodas" <neelesh.bodas (AT) gmail (DOT) com> wrote Quote: C++ guarantees that there exists a valid iterator beyond the last element of a container. However, such iterator might not be written or dereferenced. This is also true for arrays - C++ gurantees that there exists one position available beyond the end of array. Does it give similar guarantee about the position before the first element - the position indicated by the iterator rbegin()? (For arrays as well as standard containers) If you have a copy of "The C++ Standard Library" close to you, please take a look at Section 7.4.1. You will find a detailed explanation on this. Regards, Sumit. -- Sumit Rajan <sumitr (AT) msdc (DOT) hcltech.com> Back to top Neelesh Bodas Guest Posted: Mon Nov 28, 2005 2:44 pm    Post subject: Re: iterator beyond the first element Pete Becker wrote: Quote: rbegin() is completely different. Reverse iterators for containers use the end() and begin() iterators and index one off from the iterator's position. Yeah, that was a typo. And yes, I get what you are saying - you mean to say that the logical position and physical position of reverse iterators are different - they are one unit off - Is that right? If so, My confusion is resolved. Back to top Neelesh Bodas Guest Posted: Mon Nov 28, 2005 2:45 pm    Post subject: Re: iterator beyond the first element Sumit Rajan wrote: Quote: If you have a copy of "The C++ Standard Library" close to you, please take a look at Section 7.4.1. You will find a detailed explanation on this. Thanks Sumit, Just opened Josuttis' Book. :-) 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.