id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
6722,Incorrect behaviour of boost::iostreams::filtering_stream with boost::iterator_range,vadik.stepanov@…,Jonathan Turkanis,"Please consider the following code:

{{{
#include <boost/iostreams/filtering_stream.hpp>
#include <boost/range/iterator_range.hpp>
#include <sstream>

template <class Stream>
std::string read_to_string(Stream& stream)
{
   std::ostringstream destStream;
   destStream << stream.rdbuf();
   return destStream.str();
}

void main()
{
   std::istringstream sourceStream(""123"");

   std::istream_iterator<char> begin(sourceStream);
   std::istream_iterator<char> end;
   auto range = boost::make_iterator_range(begin, end);

   boost::iostreams::filtering_stream<boost::iostreams::input> sourceFilteringStream;
   sourceFilteringStream.push(range, 1);

   std::string output = read_to_string(sourceFilteringStream);
   BOOST_ASSERT(""123"" == output);
}
}}}

After each char from ""sourceStream"" it produces additional garbage char in ""output"" and triggers the assert (at least in VS10).
I've traced it to this code in boost/iostreams/detail/adapter/range_adapter.hpp:

{{{
template<>
struct range_adapter_impl<std::forward_iterator_tag> {
    template<typename Iter, typename Ch>
    static std::streamsize read
        (Iter& cur, Iter& last, Ch* s,std::streamsize n)
    {
        std::streamsize rem = n; // No. of chars remaining.
        while (cur != last && rem-- > 0) *s++ = *cur++;
        return n - rem != 0 ? n - rem : -1;
    }
    ...
}}}
""rem"" becomes -1 after the end of the while-loop and the return value after reading 1 char is 2.",Bugs,new,To Be Determined,iostreams,Boost 1.48.0,Problem,,,jeffrey.hellrung