From: mostafa_working_away@yahoo.com Date: Sat, 21 Apr 2012 17:42:26 -0700
On Fri, 20 Apr 2012 05:15:50 -0700, Olaf van der Spek <ml@vdspek.org> wrote:
What do you expect this code to do? Is b true or false? And why? Is this expected behaviour?
[1] #include <boost/range/iterator_range.hpp> [2] #include <string> [3][4] int main() [5] { [6] std::string s = "Olaf"; [7] boost::iterator_range<std::string::iterator> r(s); [8] bool a = r == s; [9] bool b = r == "Olaf"; [10] assert(a); [11] assert(b); [12] return 0; [14] }
I would expect both lines 8 and 9 to cause compilation failure. To someone unfamiliar with the library, it's not /immediately/ clear what the intent of either line is. If one wants to treat "s" as a range for the purpose of comparison, then one should explicitly adapt it to such. Ditto for line 9. It just makes the maintaining code that much easier. In the case of line 9, this has the additional benefit of forcing newcomers to ask what does make_iterator_range("Olaf") mean?, leading to a documentation look up that will preempt any potential surprises associated with char arrays and the library. [TRUNCATE] I'm guessing that Boost.Range handles the range traversal method that's acounter to the iterator traversal method. If so, I was thinking the samething Mostafa did when reading this thread: the comparisons should causecompiler errors because the types shouldn't be conceptually directlycompatible. Daryle W.