compile error on boost::iostreams::copy

Question

I'm trying to learn boost::iostreams by some examples. Here is one of them which can't be accepted by gcc:

#include <iostream>
#include <boost/iostreams/filter/regex.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/filtering_stream.hpp>
#include <boost/iostreams/device/back_inserter.hpp>

using namespace std;

int main()
{
    boost::regex reg("a.c");    
    string str("abcdef aochijk");   
    string result;
    boost::iostreams::copy(
                boost::make_iterator_range(str),    
                boost::iostreams::filtering_ostream(    
                    boost::iostreams::regex_filter(reg,"test") |    
                    boost::iostreams::back_inserter(result))    
                );
    cout<<result<<endl; 
    return 0;
}

Here is the errors:

error:no matching function for call to 'copy(boost::iterator_range<__gnu_cxx::__normal_iterator<char*, std::basic_string<char> > >, boost::iostreams::filtering_ostream)'

error:no type named 'type' in 'struct boost::disable_if<boost::iostreams::is_std_io<boost::iostreams::filtering_stream<boost::iostreams::output> >, void>'

Answer 1

My copy of clang fails to compile that as well, telling me that note: candidate function [snip] not viable: expects an l-value for 2nd argument.

That seems pretty reasonable to me, and, in fact, this compiles:

boost::regex reg("a.c");    
string str("abcdef aochijk");
string result;
boost::iostreams::filtering_ostream ios(    
                boost::iostreams::regex_filter(reg,"test") |    
                boost::iostreams::back_inserter(result));
boost::iostreams::copy( boost::make_iterator_range(str), ios);