Reversing the content of an input stream.

gistfile1.cpp

#include <iostream>
#include <sstream>
#include <vector>
#include <iterator>

template<class charT>
class reverse_buffer : public std::basic_stringbuf<charT>
{
    typedef std::basic_stringbuf<charT> streambuf_type;
    typedef typename streambuf_type::int_type int_type;
    typedef typename streambuf_type::traits_type traits_type;
public:
    reverse_buffer(std::basic_streambuf<charT>* sbptr)
    {
        std::basic_ostringstream<charT> buf;
        buf << sbptr;
        
        std::basic_string<charT> rev = buf.str();
        std::copy(rev.rbegin(), rev.rend(), std::ostreambuf_iterator<charT>(&sb));
    }
    
    int_type underflow()
    {
        ch = traits_type::to_char_type(sb.sbumpc());
        this->setg(&ch, &ch, &ch + 1);
        return ch;
    }
private:
    charT ch;
    streambuf_type sb;
};

std::istringstream iss("hello world how are you?");

int main()
{
    reverse_buffer<char> rbuf(iss.rdbuf());
    std::istream is(&rbuf);
    std::vector<std::string> v;
    std::istream_iterator<std::string> beg(is), end;
    std::copy(beg, end, std::back_inserter(v));
}