Re: [Boost-users] [boost::transform_iterator] failure with std::vector::const_iterator

From: shunsuke (pstade.mb_at_[hidden])
Date: 2007-03-04 21:41:04

Ovanes Markarian wrote:
> Hello!
> 
>  
> 
> I have an assertion failure using std::vector::const_iterator and
> boost::transform_iterator.
> 
> I have a constant seq of constant string pairs delimited by special
> character (here ':'). My application needs only once to iterate through
> these pairs and return iterator ranges from the beginning until the colon
> and after colon until the end. I thought a transform iterator can do the
> job. I get in the marked position an assertion failure using MSVC 2005
> Express Edition.
> 
> 
> Here the code snippet with problem description:
> 
> 
> #include <string>
> #include <vector>
> #include <utility>
> #include <functional>
> 
> #include <boost/iterator/transform_iterator.hpp>
> #include <boost/range/iterator_range.hpp> 
> #include <boost/utility.hpp> 
> #include <boost/bind.hpp>
> 
> typedef boost::iterator_range<std::string::const_iterator>
> iter_range;
> typedef std::pair<iter_range,iter_range>
> result_type;
> 
> struct string_splitter : std::unary_function<std::string const&,
> result_type> 
> {
> 	result_type operator()(std::string const& s)const throw()
> 	{
> 		iter_range r1(s.begin(), s.begin() + s.find(":"));
> 		iter_range r2(r1.end()+1, s.end());
> 		return result_type(r1,r2);
> 	}
> };
> 
> typedef std::vector<std::string>
> str_vector;
> typedef str_vector::const_iterator
> vector_citer;
> typedef boost::transform_iterator<string_splitter, vector_citer>
> msg_opcode_citer;
> 
> int main()
> {
> 	//create vector of strings and put 2 strings inside
> 	str_vector v;
> 	v.push_back(std::string("test1:opcode1"));
> 	v.push_back(std::string("test2:opcode2"));
> 
> 	//!!!increment operator or dereference operator cause an assertion
> failure!!!
> 	// stating: "vector iterators incompatible"
> 	for(msg_opcode_citer curr = msg_opcode_citer(const_cast<str_vector
> const&>(v).begin(), string_splitter()), end; 
> 			curr != end; ++curr)
> 	{
> 		result_type t = *curr;
> 	}
> 
> 	return 0;
> }
> 
> 
> Did I miss something?

'end' seems not initialized.
Try..

     for(msg_opcode_citer curr = msg_opcode_citer(boost::const_begin(v), 
string_splitter()),
         end = msg_opcode_citer(boost::const_end(v), string_splitter());
                        curr != end; ++curr)
        {
                result_type t = *curr;
        }

Regards,

-- 
Shunsuke Sogame